U.S. Department of Justice
Office of Justice Programs
National Institute of Justice
Walk-Through Metal Detector Standard for Public Safety
NIJ Standard-0601.03
January 2011
NCJ xxxxx
U.S. Department of Justice
Office of Justice Programs
National Institute of Justice
John H. Laub
Director
Ellen Scrivner
Deputy Director
Davis Hart
Division Director, Operational Technologies Division
Debra Stoe
Physical Scientist, Operational Technologies Division
Frances Scott
Physical Scientist, Information Sensor and Technology Division
The preparation of this document was sponsored by the National Institute of Justice.
The National Institute of Justice is a component of the Office of Justice Programs, which also includes the Bureau
of Justice Assistance; the Bureau of Justice Statistics; the Community Capacity Development Office; the Office for
Victims of Crime; the Office of Juvenile Justice and Delinquency Prevention; and the Office of Sex Offender
Sentencing, Monitoring, Apprehending, Registering, and Tracking (SMART).
Walk-Through Metal Detector Standard for Public Safety
Special Technical Committee
This standard was developed by a Special Technical Committee of practitioners, technical
experts, and others with experience in standards development and conformity assessment.
Committee members, their organizations and their professional affiliations are listed in Table 1
and Table 2.
Table 1. Practitioners
Type
Name
Organization
Professional Affiliation
Table 2. Technical Experts and Others
Type
Name
Organization
iii
Expertise
Walk-Through Metal Detector Standard for Public Safety
Advisory Working Group
The work of the Special Technical Committee was reviewed by an Advisory Working Group
(AWG) made up of senior-level representatives from stakeholder organizations and individuals
with experience in standards development and conformity assessment. Members and their
organizations are listed in Table 3 below.
Table 3. AWG Members
Member
Organization
iv
Title
Walk-Through Metal Detector Standard for Public Safety
FOREWORD
This document is a voluntary performance standard published by the National Institute of Justice (NIJ) for
walk-through metal detectors used by public safety. It defines both performance requirements and the
methods used to test performance. Details on the test objects required for testing may be found in NIJ
Report 100-07, Metal Detector Test Objects Report. In order for a manufacturer or other entity to claim
that a particular hand-held metal detector model satisfies this NIJ standard, the model must be in
compliance with this standard as determined in accordance with this document and the associated
document, Public Safety Walk-Through Metal Detector Certification Program Requirements, NIJ CR0601.03. Both this standard and the associated certification program requirements document are produced
as a part of the Standards and Testing Program of the U.S. Department of Justice, Office of Justice
Programs, NIJ, as is a third associated document, the Public Safety Selection and Application Guide to
Walk-Through Metal Detectors, NIJ Guide-0601.03.
All requirements stated in this standard, including those that explicitly employ mandatory language (e.g.,
“shall”) are those necessary to satisfy the standard. Nothing in this document is intended to require or
imply that commercially available walk-through metal detectors for use by public safety must satisfy this
standard.
This document is a performance and testing standard and, therefore, provides precise and detailed test
methods.
Publication of NIJ Standard-0602.03 does not render unsuitable or obsolete any walk-through metal
detectors currently in use by public safety agencies. Although NIJ is not suggesting the removal of any
existing walk-through metal detectors from service, agencies are advised to require that future
procurements specify that equipment shall meet or exceed the most recent version of this standard.
NIJ standards are subject to continued research, development and testing, and to review and modification
as appropriate on an ongoing basis. Users of this standard are advised to check www.justnet.org on a
regular basis to determine whether it has been revised or superseded.
Technical comments and recommended revisions are welcome. Please send all written comments and
suggestions to Director, National Institute of Justice, Office of Justice Programs, U.S. Department of
Justice, 810 Seventh St., N.W., Washington, DC 20531.
______________
Nothing in this document is intended to create any legal or procedural rights enforceable against the
United States. Moreover, nothing in this document creates any obligation for manufacturers, law
enforcement agencies, or others to follow or adopt this voluntary law enforcement technology equipment
standard.
v
Walk-Through Metal Detector Standard for Public Safety
CONTENTS
1. SCOPE, PURPOSE AND APPLICATION........................................................ 1 1.1 Scope .................................................................................................................. 1 1.2 Purpose ............................................................................................................... 1 1.3 Application ......................................................................................................... 2 2. REFERENCES ................................................................................................... 3 2.1 Associated Publications...................................................................................... 3 2.2 Referenced Publications ..................................................................................... 3 2.3 American Conference of Governmental Industrial Hygienists Publications ..... 3 2.4 American National Standards Institute Publications .......................................... 3 2.5 International Commission on Illumination Publications .................................... 3 2.6 International Electrotechnical Commission Publications .................................. 3 2.7 National Institute of Justice (NIJ) Publications.................................................. 5 2.8 National Institute of Standards and Technology (NIST) Publications ............... 5 2.9 U.S. Military Publications .................................................................................. 5 3. DEFINITIONS ................................................................................................... 7 3.1 General ............................................................................................................... 7 3.2 Standard-Specific Definitions ............................................................................ 7 4. FORM AND FIT REQUIREMENTS............................................................... 15 4.1 WTMD Model Requirements........................................................................... 15 4.2 Controls and Adjustments for WTMD Models ................................................ 16 4.3 Indication Requirements for WTMD Models .................................................. 16 4.4 Equipment Protection Requirements for WTMD Models ............................... 16 5. PERFORMANCE REQUIREMENTS............................................................. 17 5.1 Acceptance Criteria .......................................................................................... 17 5.2 Safety Requirements ........................................................................................ 17 5.3 Detection Performance Requirements .............................................................. 18 5.4 WTMD Demonstration Requirements ............................................................. 19 5.5 Operator Control Requirements ....................................................................... 20 vii
Walk-Through Metal Detector Standard for Public Safety
5.6 Program Storage Requirements ........................................................................ 20 5.7 Alarm Indicator Requirements ......................................................................... 20 5.8 Status Alarm Indicator Tests ............................................................................ 20 5.9 Metallic Interference Requirements ................................................................. 21 5.10 Electrical Requirements ................................................................................... 21 5.11 Mechanical Requirements for Resistance to Shock ......................................... 22 5.12 Environmental Requirements ........................................................................... 22 5.13 Electromagnetic Interference Requirements .................................................... 23 6. TEST METHODS ............................................................................................ 25 6.1 General Test Requirements .............................................................................. 25 6.2 General Test Conditions ................................................................................... 25 6.3 Test Objects and Equipment ............................................................................ 25 6.4 Safety Tests ...................................................................................................... 27 6.5 Detection Performance Tests ........................................................................... 27 6.6 WTMD Demonstration Test............................................................................. 33 6.7 Operator Control Test....................................................................................... 34 6.8 Program Storage Test ....................................................................................... 34 6.9 Audible Alarm Indicator Test .......................................................................... 34 6.10 Visible Alarm Indicator Test ............................................................................ 35 6.11 Metal Object Detection Alarm Indicator Test .................................................. 35 6.12 System Status Alarm Indicator Test ................................................................. 35 6.13 Detection Ready State Alarm Indicator Test.................................................... 35 6.14 Speed Range Violation Alarm Indicator Test (Optional)................................. 36 6.15 Electrical Tests ................................................................................................. 36 6.16 Test for Operation Near a Stationary Metal Object ......................................... 37 6.17 Test for Operation Near a Steel Floor .............................................................. 37 6.18 Test for Operation Near Steel Reinforced Floor .............................................. 38 6.19 Metallic Moving Object Test (Metal Door Interference Test) ......................... 38 6.20 Multiple Object Interference Test .................................................................... 39 6.21 Mechanical Resistance to Shock Test .............................................................. 40 6.22 Indoor or Sheltered Outdoor Temperature Stability and Range Test............... 40 viii
Walk-Through Metal Detector Standard for Public Safety
6.23 Outdoor Temperature Stability and Range Test ............................................... 40 6.24 Relative Humidity Stability and Range Test .................................................... 40 6.25 Environmental Protection, Indoor Test ............................................................ 40 6.26 Environmental Protection, Sheltered Outdoor Test ......................................... 40 6.27 Environmental Protection, Outdoor Test ......................................................... 41 6.28 Radiated Emissions Test .................................................................................. 41 6.29 Conducted Emissions Test ............................................................................... 41 6.30 Radiated Magnetic Field Test (Low-Frequency Magnetic Field Susceptibility
Test) .................................................................................................................. 41 6.31 Radiated RF Electromagnetic Field Immunity Test ......................................... 43 6.32 60 Hz Radiated Magnetic Field Test ................................................................ 43 6.33 Electrostatic Discharge Test ............................................................................. 43 6.34 Fast Transients Test .......................................................................................... 43 6.35 Surge Test ......................................................................................................... 44 6.36 RF Common Mode Test ................................................................................... 44 6.37 Voltage Interruptions and Dips Test ................................................................ 44 7. LABELING AND INFORMATION................................................................ 45 7.1 General Product Label Requirements .............................................................. 45 7.2 User Information to Be Provided by the Manufacturer of the WTMD ............ 45 APPENDIX: INNOCUOUS ITEM TEST OBJECTS ............................................................. 47 EQUATIONS
Equation 1: Average position. ...................................................................................... 42 FIGURES
Figure 1. Diagram of Walk-Through Metal Detector .................................................... 8 Figure 2. WTMD Front View ...................................................................................... 10 Figure 3. WTMD Side View ........................................................................................ 11 Figure 4. Specific Test Measurement Locations .......................................................... 12 Figure 5. Mechanical Drawing of Eyeglass Replica .................................................... 48 Figure 6: Innocuous Item Test Object Locations. ........................................................ 49 ix
Walk-Through Metal Detector Standard for Public Safety
ABBREVIATIONS, SYMBOLS, PREFIXES AND CONVERSIONS
ACGIH
ASTM
CIE
IEC
ISO
MIL-STD
NLECTC
NIJ
NIST
OLES
OSHA
TOP
WTMD
X
xi
Y
yi
American Conference of Government Industrial Hygenists
American Society for Testing and Materials International
International Commission on Illumunation
International Electrotechnical Commission
International Standards Organization
Military Standard
National Law Enforcement and Corrections Technology Center
National Institute of Justice
National Institute of Standards and Technology
Office of Law Enforcement Standards
Occupational Safety and Health Administration
Test Operations Procedure
Walk-Through Metal Detector
Average of the adjacent horizontal zone widths
Horizontal zone width
Average of adjacent vertical zone spans
Vertical zone span
Commonly Used Symbols and Abbreviations
A
ac
AM
cd
cm
CP
c/s
d
dB
dc
°C
°F
diam
emf
eq
F
fc
fig.
FM
ft
ft/s
g
g
gr
ampere
alternating current
amplitude modulation
candela
centimeter
chemically pure
cycle per second
day
decibel
direct current
degree Celsius
degree Fahrenheit
diameter
electromotive force
equation
farad
footcandle
figure
frequency modulation
foot
foot per second
acceleration
gram
grain
H
h
hf
Hz
i.d.
in
IR
J
kN
L
Lb
lbf
lbf⋅in
lm
ln
log
M
m
min.
mm
mph
m/s
N
N⋅m
henry
hour
high frequency
hertz
inside diameter
inch
infrared
joule
Kilo newton
liter
pound
pound force
pound force inch
lumen
logarithm (base e)
logarithm (base 10)
molar
meter
minute
millimeter
miles per hour
meter per second
newton
newton meter
nm
No.
o.d.
Ω
p.
Pa
pe
pp.
ppm
qt
rad
rf
rh
s
SD
sec.
SWR
uhf
UV
V
vhf
W
λ
wt
area = unit2 (e.g., ft2, in2, etc.); volume = unit3 (e.g., ft3, m3, etc.)
x
nanometer
number
outside diameter
ohm
page
pascal
probable error
pages
parts per million
quart
radian
radio frequency
relative humidity
second
standard deviation
section
standing wave ratio
ultrahigh frequency
ultraviolet
volt
very high frequency
watt
wavelength
weight
Walk-Through Metal Detector Standard for Public Safety
Prefixes
d
c
m
µ
n
p
deci (10-1)
centi (10-2)
milli (10-3)
micro (10-6)
nano (10-9)
pico (10-12)
da
h
k
M
G
T
deka (10)
hecto (102)
kilo (103)
mega (106)
giga (109)
tera (1012)
Common Conversions
0.30480 m = 1 ft
2.54 cm = 1 in
0.4535924 kg = 1 lb
0.06479891 g = 1 gr
0.9463529 L = 1 qt
3600000 J = 1 kW⋅h
4.448222 N = 1 lbf
1.355818 J = 1 ft⋅lbf
0.1129848 N.m = 1 lbf⋅in
14.59390 N/m = 1 lbf/ft
6894.757 Pa = 1 lbf/in2
1.609344 km/h = 1 mph
xi
Walk-Through Metal Detector Standard for Public Safety
1.
SCOPE, PURPOSE AND APPLICATION
1.1
Scope
1.1.1
This document is a voluntary standard. All requirements stated in this standard,
including those that explicitly employ mandatory language (e.g., “shall”) are those
necessary to satisfy the standard. Nothing in this document is intended to require or
imply that commercially available walk-through metal detectors (WTMDs) used by
public safety must satisfy this standard. In order for a manufacturer or other entity to
claim that a particular WTMD model satisfies this NIJ standard, however, the model
must be found to comply with this standard as determined in accordance with this
document and the associated document, Public Safety Walk-through Metal Detector
Certification Program Requirements, NIJ CR-0601.03.
1.1.2
This standard specifies the minimum requirements for form and fit, performance,
testing, documentation, and labeling of active WTMDs used by public safety to detect
concealed metallic weapons and contraband.
1.1.3
This standard shall establish requirements for new, unused WTMDs.
1.1.4
This standard shall not be understood as addressing all of the safety concerns
associated with the use of WTMDs used by public safety.
1.1.5
This standard shall not be understood as addressing the safety concerns, if any,
associated with the use of this standard by testing facilities.
1.1.6
No manufacturer or other entity shall claim compliance with only selected portions of
this standard. The WTMD model shall meet all applicable stated requirements.
1.1.7
As appropriate (e.g., for models that employ materials or forms of construction that
were not anticipated when this standard was developed or are not addressed by this
standard), NIJ may modify the test methods of the standard or establish new ones.
1.1.8
Nothing herein shall be understood to restrict any WTMD manufacturer from
exceeding the requirements of this standard.
1.2
Purpose
1.2.1
The purpose of this standard is to specify minimum performance requirements and
methods for testing active WTMDs used by public safety for the detection of metallic
weapons or contraband carried on a person and/or concealed by a nonmetal object.
1
Walk-Through Metal Detector Standard for Public Safety
1.2.2
The purpose of the test methods in this standard is to assess performance and should
not be understood to specify performance levels for all situations and hazards to
which public safety personnel may be exposed.
1.2.3
This standard is not intended to be used as a detailed manufacturing or purchase
specification but may be referenced in purchase specifications as minimum
requirements.
1.3
Application
1.3.1
This standard provides for three classifications of WTMDs based on the test objects
can be detected by the WTMD: MD Class 1, MD Class 2 and MD Class 3 (See
Section 3.2.21).
1.3.2
All measurement units used in this document are metric. Length units are
abbreviated: meter (m), centimeter (cm) and millimeter (mm). Where useful, English
units are indicated in parentheses immediately following the metric units, such as
“2.54 cm (1 in).”
2
Walk-Through Metal Detector Standard for Public Safety
2.
REFERENCES
2.1
Associated Publications
The following document is a companion publication to NIJ Standard-0601.03, NIJ
Report 100-07, and NIJ CR-0601.03.
NIJ Guide-0601.03, Public Safety Selection and Application Guide to Walk-through
Metal Detectors, Washington, DC: U.S. Department of Justice, National Institute of
Justice.
2.2
Referenced Publications
The following references form a basis and provide support for the requirements and
procedures described in this standard. For dated references, only the edition cited
applies. For undated references, the latest edition of the referenced document applies,
including any amendments.
2.3
American Conference of Governmental Industrial Hygienists Publications
2.3.1
ACGIH-0302:1996. Documentation of the Threshold Limit Values, Sub-Radio
Frequency (30 kHz and below) Magnetic Fields. Cincinnati, OH: American
Conference of Governmental Industrial Hygienists.
2.4
American National Standards Institute Publications
2.4.1
ANSI/ISA-61010-1:2005. 2005. Safety Requirements for Electrical Equipment for
Measurement Control and Laboratory Use – Part 1: General Requirements.
Washington, DC: American National Standards Institute.
2.4.2
ANSI/NEMA WD 6:2002. 2002. American National Standards Institute and National
Electrical Manufacturing Association. Wiring Devices - Dimensional Specifications.
Washington, DC: American National Standards Institute.
2.4.3
ANSI S1.4:1983. 1983. Specifications for General Purpose Sound Level Meters.
Washington, DC: American National Standards Institute.
2.5
International Commission on Illumination Publications
2.5.1
ISO/CIE 23539:2005. 2005. Photometry – The CIE System of Physical Photometry.
Vienna, Austria: Commission Internationale de l´Eclairage.
2.6
International Electrotechnical Commission Publications
2.6.1
CISPR 22. 2008. Information Technology Equipment – Radio Disturbance
Characteristics – Limits and Methods of Measurement. Geneva, Switzerland:
International Electrotechnical Commission.
3
Walk-Through Metal Detector Standard for Public Safety
2.6.2
IEC 60068–2–27. 2008. Basic Environmental Testing Procedures, Part 2-27: Tests –
Test Ea and Guidance: Shock. Geneva, Switzerland: International Electrotechnical
Commission.
2.6.3
IEC 60068-2-30. 2005. Environmental Testing, Part 2-30: Tests – Test Db: Damp
Heat, Cyclic (12 h + 12 h Cycle). Geneva, Switzerland: International Electrotechnical
Commission.
2.6.4
IEC 60529. 2001. Degrees of Protection Provided by Enclosures (IP Code). Geneva,
Switzerland: International Electrotechnical Commission.
2.6.5
IEC 61000-4-2. 2001. Electromagnetic Compatibility (EMC), Part 4-2: Testing and
Measurement Techniques – Electrostatic Discharge Immunity Test. Geneva,
Switzerland: International Electrotechnical Commission.
2.6.6
IEC 61000-4-3. 2008. Electromagnetic Compatibility (EMC), Part 4-3: Testing and
Measurement Techniques – Radiated, Radio-Frequency, Electromagnetic Field
Immunity Test. Geneva, Switzerland: International Electrotechnical Commission.
2.6.7
IEC 61000-4-4. 2001. Electromagnetic Compatibility (EMC), Part 4-3: Testing and
Measurement Techniques – Radiated, Radio-Frequency, Electromagnetic Field
Immunity Test. Geneva, Switzerland: International Electrotechnical Commission.
2.6.8
IEC 61000-4-5. 2004. Electromagnetic Compatibility (EMC), Part 4-5: Testing and
Measurement Techniques – Surge Immunity Test. Geneva, Switzerland: International
Electrotechnical Commission.
2.6.9
IEC 61000-4-6. Electromagnetic Compatibility (EMC, Part 4-6: Testing and
Measurement Techniques - Immunity to Conducted Disturbances, Induced by RadioFrequency Fields. Geneva, Switzerland: International Electrotechnical Commission.
2.6.10
IEC 61000-4-8. 2001. Electromagnetic Compatibility (EMC), Part 4-8: Testing and
Measurement Techniques – Power Frequency Magnetic Field Immunity Test.
Geneva, Switzerland: International Electrotechnical Commission.
2.6.11
IEC 61000-4-11. 2004. Electromagnetic Compatibility (EMC), Part 4-11: Testing
and Measurement Techniques – Voltage Dips, Short Interruptions and Voltage
Variations Immunity Tests. Geneva, Switzerland: International Electrotechnical
Commission.
2.6.12
IEC 61000-6-1. 2005. Electromagnetic Compatibility – Generic Immunity Standard,
Part 1: Residential, Commercial, and Light Industry. Geneva, Switzerland:
International Electrotechnical Commission.
2.6.13
IEC 61000-6-3. 2006. Electromagnetic Compatibility – Generic Emission – Emission
Standard for Residential, Commercial, and Light-Industrial Environments. Geneva,
Switzerland: International Electrotechnical Commission.
4
Walk-Through Metal Detector Standard for Public Safety
2.7
National Institute of Justice (NIJ) Publications
2.7.1
NIJ CR-0601.03, Public Safety Walk-Through Metal Detector Certification Program
Requirements. Washington, DC: U.S. Department of Justice, National Institute of
Justice.
2.7.2
NIJ Report 100-07. Metal Detector Test Object. Washington, DC: U.S. Department of
Justice, National Institute of Justice.
2.8
National Institute of Standards and Technology (NIST) Publications
2.8.1
NIST Technical Note 1297. 1994. Guidelines for Evaluating and Expressing the
Uncertainty of NIST Measurement Results. Gaithersburg, MD: National Institute of
Standards and Technology.
2.9
U.S. Military Publications
2.9.1
MIL-STD-810F:2000 Method 501.4. 2000. Test Method Standard for Environmental
Engineering Considerations and Laboratory Tests, Method 501.4, High Temperature.
Washington, DC: U.S. Department of Defense.
2.9.2
MIL-STD-810F:2000 Method 502.4. 2000. Test Method Standard for Environmental
Engineering Considerations and Laboratory Tests, Method 502.4, Low Temperature.
Washington, DC: U.S. Department of Defense.
5
Walk-Through Metal Detector Standard for Public Safety
3.
DEFINITIONS
3.1
General
The definitions contained in this chapter shall apply to these terms as used in this
standard. Where terms are not defined in this chapter or within another chapter, they
shall be defined using their ordinarily accepted meanings within the context in which
they are used.
3.2
Standard-Specific Definitions
3.2.1
Alarm indication instance: The time in the recorded waveform of the alarm
indication at which the alarm indication changes states.
3.2.1.1
Final alarm indication instance: The instant when the alarm indication changes
from the on-state to the off-state as the test object is moving away from the WTMD.
3.2.1.2
Initial alarm indication instance: The instant when the alarm indication changes
from the off-state to the on-state as the test object is moving toward the WTMD.
3.2.2
Alarm indication: A signal to the operator indicating the detection of a metal object.
3.2.3
Alarm indicator: A visible or audible device used to provide awareness of detection
of a metal object.
3.2.4
Alarm reset time: The amount of time required for the WTMD to be ready to sense
another metallic test object after sensing a first metallic test object.
3.2.5
Calibration artifacts: Objects used to transfer standardization from one system to
another and/or from one time to another. These objects are defined by the WTMD
manufacturer and used to provide traceability to documented results.
3.2.6
Care: Cleaning, decontamination and storage of WTMDs.
3.2.7
Clean test subject: A person who is verified not to be carrying any electrically
conductive or magnetizable objects such as metallic belt buckles, metal buttons, a
cardiac pacemaker, coins, metal-frame eyeglasses, a hearing aid, jewelry, keys, pens,
pencils, shoes with metal arches or supports, metallic surgical implants, undergarment
support metal, metal zippers, or similar items that would significantly alter the signal
produced when this person carries a test object.
3.2.7.1
Alternative: A clean test subject may be replaced by a human simulator that
approximates the mass and mass distribution of an average adult male. The human
simulator shall be constructed of carbon impregnated fuoroelastomer with a
conductivity of approximately 0.25 S/m over a range of 200 Hz to 3 MHz. The
human simulator shall be equipped with casters and a means to push it through the
detector at speeds between 0.2 m/s ± 0.1 m/s and 2.0 m/s ± 0.1m/s.
7
Walk-Through Metal Detector Standard for Public Safety
3.2.8
Detection: The discovery or finding of a metallic object.
3.2.8.1
Detector axis: An imaginary line passing through and perpendicular to the WTMD’s
plane. This line is centered vertically and horizontally within the portal and points in
the direction of the test subject’s motion through the portal. (See Figure 1.)
3.2.8.2
Detector floor: The bottom plane of the WTMD’s portal, which rests on the top
surface of the WTMD’s platform.
3.2.8.3
Detector plane: An imaginary two-dimensional surface parallel to the portal that
bisects the sensor region into two symmetric halves. This “surface” contains two
orthogonal axes labeled as the x axis and the z axis. (See Figure 1.)
3.2.8.4
Detector platform: A nonconductive, nonmagnetic platform on which the WTMD
rests. The WTMD mount locates the detector floor at a height of 32.5 cm (12.8 in)
and contains grooves or a shelf located at 10 cm (4 in) below its top surface to
facilitate the metal floor test required in Section 6.15.
Figure 1. Diagram of Walk-Through Metal Detector
z axis
detector axis
detector plane
x axis
detector floor
y axis
8
Walk-Through Metal Detector Standard for Public Safety
3.2.9
Detector response: An electrical signal generated by the sensor or sensor circuit of a
walk-through metal detector, caused by a metallic object interacting with the
magnetic field generated by the device; the basis on which an alarm indication is
derived.
3.2.10
Manufacturer: A commercial enterprise engaged in fabricating a product.
3.2.11
Maintenance: Inspection, repair and retirement of WTMDs.
3.2.12
Measurement coordinate system: A mutually orthogonal three-dimensional
Cartesian scheme referenced to the detector axis and the detector plane. The three
axes are labeled x-axis, y-axis and z-axis, where the y-axis is parallel to the detector
axis, and the x and z axes are located in the detector plane. The origin of the x-y-z
axes is located on the detector floor midway between the sides of the portal. The
orientation of the test objects and direction of the magnetic field is referenced to this
scheme. (See Figure 1.)
3.2.13
Minimum detection condition: During the Detection Sensitivity Test (refer to
Section 5.3.2), each test measurement grid location has a recorded maximum
detection signal for each test object at each orientation. From those recorded
maximum detection signals, indicate the lowest of those values for each test object at
each orientation. For that lowest value, record the test object, orientation and test
measurement grid location as the minimum detection condition for a single object
class. The result is one minimum detection condition per test object class.
3.2.14
Model: The manufacturer’s design, with unique specifications and characteristics, of
a particular item.
3.2.15
Object classes: A categorization scheme based on the ability to detect metal objects
of a certain size and electromagnetic characteristics. A WTMD may meet the
requirements for one, two or three object classes: MD Class 1, MD Class 2 and MD
Class 3. (Refer to Test Object definitions in Section 3.2.21.)
3.2.16
Portal: The open area of the WTMD through which a person walks to be assessed for
the presence of metallic objects. Refer to Figure 2 and Figure 3.
3.2.16.1
Portal depth: Distance between the portal entry face and the portal exit face.
3.2.16.2
Portal entry face: The first edge of the portal that a person or a test object passes
during the detection process.
3.2.16.3
Portal exit face: The last edge of the portal that a person or a test object passes
during the detection process.
3.2.16.4
Portal height: The distance between the detector floor and the ceiling of the portal.
9
Walk-Through Metal Detector Standard for Public Safety
3.2.16.5
Portal width: The distance between the interior sides or walls of the portal.
3.2.17
Product: One unit of a particular model.
3.2.18
Product label: A marking affixed by a manufacturer to each unit of a compliant
model or to the compliant model package, which contains required model information
and the mark of conformity.
3.2.19
Sample: A WTMD that is subjected to testing. A sample is to be representative of a
model.
3.2.20
Specific test measurement location: The nine positions in the detector plane (x-z
plane) through which the test object(s) shall be passed. These positions are based on
the size of an average adult male and are defined at points along the x-axis and z-axis
of the coordinate system. There are two positions at ankle height separated
approximately by hip width, two at hip height separated approximately by hip width,
two at shoulder height separated approximately by torso width, one at top of head
height centered along the z-axis, one at slightly below armpit height centered along
the z-axis and one at crotch height centered along the z-axis. (See Figure 4.) These
positions are a subset of the test measurement grid locations.
Figure 2. WTMD Front View
10
Walk-Through Metal Detector Standard for Public Safety
Figure 3. WTMD Side View
3.2.21
Test object: An item used to assess the detection performance of a WTMD. It may
simulate a threat or be an innocuous item as defined below:
3.2.21.1
MD Class 1 test objects: Items used to test the detection performance of WTMDs
that locate items nominally the size of a handgun. MD Class 1 test objects were
previously referred to as large size test objects.
3.2.21.2
MD Class 2 test objects: Items used to test the detection performance of WTMDs
that locate items nominally the size of a paring knife. MD Class 2 test objects were
previously referred to as medium size test objects.
3.2.21.3
MD Class 3 test objects: Items used to test the detection performance of WTMDs
that locate items such as short sections of hacksaw blades, hand-held paint scraper
blades, small stainless steel knives, screwdriver bits, small caliber ammunition and
handcuff keys. MD Class 3 test objects were previously referred to as small size test
objects.
11
Walk-Through Metal Detector Standard for Public Safety
3.2.21.4
Innocuous item test objects: Items used to test the discrimination capability of MD
Class 1 and MD Class 2 WTMDs. Details for the innocuous items are provided in
Appendix A.
3.2.22
Test measurement grid location: Grid pattern with its origin at the intersection of
the x-z axes and with 5 cm ± 0.5 cm spaces located within the detector plane (See
Section 3.2.12). The z-axis limits are 0 cm + 0.5 cm/- 0 cm and 180 cm ± 1.0 cm. The
x-axis limits shall be as close as possible to 10 cm ± 0.5 cm from the inside surfaces
of each of the WTMD’s sides.
Figure 4. Specific Test Measurement Locations
12
Walk-Through Metal Detector Standard for Public Safety
3.2.23
Test object axes: Three mutually orthogonal lines that are referenced to, and have a
one-to-one correspondence with, the corresponding lines of the measurement
coordinate system.
3.2.24
Three-axis positioning system: A scheme providing mutually orthogonal directions
of linear translation used to place test objects in the WTMD’s magnetic field. A
Cartesian robot may be used in this scheme, but is not required.
3.2.25
Throughput rate: The amount of time required for the WTMD to be ready to sense a
metallic test object after sensing an innocuous test object.
3.2.26
Verification test: An abbreviated set of performance tests used to ensure the
WTMD’s performance prior to use.
3.2.27
Walk-through metal detector (WTMD): A device using magnetic induction to
detect objects of specific types. The device generates energy within its portal and
contains source electronics that generate a magnetic field and detector electronics that
sense magnetic fields. The interaction of the generated magnetic field with certain
types of objects in the portal and the ability to detect this interaction is the basis of
operation.
3.2.28
WTMD manufacturer: Supplier of a WTMD who submits a model for certification.
13
Walk-Through Metal Detector Standard for Public Safety
4.
FORM AND FIT REQUIREMENTS
To be tested under the performance requirements of this standard, WTMD models
shall satisfy the requirements of this chapter.
4.1
WTMD Model Requirements
4.1.1
The WTMD shall be designed to detect metallic concealed weapons and contraband
items passing through the detector portal.
4.1.2
The WTMD shall be classified by the WTMD manufacturer as MD Class 1, MD
Class 2 and/or MD Class 3 (Refer to NIJ Report 100-07).
4.1.2.1
If the WTMD is classified by the WTMD manufacturer for multiple classes, the
WTMD shall be designed with a sensitivity adjustment and shall be tested for each
MD Class.
4.1.3
The intended operating environment for the WTMD shall be specified by the WTMD
manufacturer as indoor, outdoor sheltered or outdoor, and the WTMD shall be tested
according to the appropriate requirements of Section 5.12.
4.1.4
The WTMD shall be designed so that the portal meets the following dimensional
limits:
•
Portal height, minimum: 195 cm (77 in).
•
Portal width, minimum: 71 cm (28 in).
•
Portal depth, maximum: 91 cm (36 in).
4.1.5
The WTMD shall have a mass no greater than 100 kg (220 lbs).
4.1.6
The WTMD shall be provided with an input power connector socket on both sides of
the WTMD, unless the operation and function of the WTMD is the same for traffic
flow in both directions, in which case an input power connector is required only on
one side of the portal. To provide a secure connection, the power connector socket
shall not be exposed and shall provide a means to prevent unintentional disconnection
of the power cord.
4.1.7
The WTMD shall have an electrical connector from which either an analog or digital
output signal is obtained. This signal represents the magnitude of the detector
response to a test object and is the signal on which an alarm indication is based. If the
output signal is analog, the connector shall be coaxial where the inner conductor
provides the signal path and the outer conductor provides signal ground or return.
4.1.8
Calibration artifacts shall be provided by the WTMD manufacturer for each WTMD.
The WTMD manufacturer shall define the x-z test positions and calibration artifact
15
Walk-Through Metal Detector Standard for Public Safety
orientations, if applicable, for which the WTMD shall be tested with each calibration
artifact. The WTMD manufacturer shall record the magnitude of the detection
response from the WTMD for a pass of each calibration artifact and its specified
orientation(s) through the portal at each test location.
4.2
Controls and Adjustments for WTMD Models
4.2.1
With the exception of the power on/off switch and audio alarm on/off switch, controls
and adjustments that affect the performance of the WTMD (e.g., sensitivity settings)
shall be capable of being secured against access by the operator.
4.3
Indication Requirements for WTMD Models
4.3.1
The WTMD shall be designed to provide visible and audible alarm indication in the
event that a metallic object within the appropriate object class is detected.
4.4
Equipment Protection Requirements for WTMD Models
4.4.1
All circuits, wiring or cables (other than input power cables) shall be enclosed.
16
Walk-Through Metal Detector Standard for Public Safety
5.
PERFORMANCE REQUIREMENTS
5.1
Acceptance Criteria
5.1.1
To declare conformity with this standard, all performance requirements defined in the
following sections shall be met for each of the categories listed below:
•
Safety requirements (Section 5.2).
•
Detection performance requirements (See Section 5.3).
•
Operator control requirements (See Section 5.4).
•
Program storage requirements (See Section 5.6).
•
Alarm indicator requirements (See Section 5.7).
•
Status indicator requirements (See Section 5.8).
•
Metallic interference requirements (See Section 5.9).
•
Electrical requirements (See Section 5.10).
•
Mechanical requirements (See Section 5.11).
•
Environmental requirements (See Section 5.12).
•
Electromagnetic interference requirements (See Section 5.13).
5.1.2
The WTMD shall meet the detection performance requirements for each MD Class
for which it is intended to operate.
5.1.3
The detection performance shall be evaluated by the test methods described in
Section 6, and all tests referenced in this section shall include the requirements of
Sections 6.1 and 6.2.
5.1.4
The safety tests shall be performed first, followed by the detection performance tests.
Environmental tests shall follow mechanical tests on a single unit. No other specific
test sequence is required.
5.2
Safety Requirements
5.2.1
The WTMD shall meet the fire, electrical, thermal and mechanical safety
requirements of ANSI/ISA-61010-1, as applicable.
5.2.2
The WTMD shall comply with the magnetic field exposure requirements as specified
in ACGIH–0302:1996, as amended.
17
Walk-Through Metal Detector Standard for Public Safety
5.3
Detection Performance Requirements
5.3.1
The WTMD shall be tested as specified in Section 6.5, Detection Performance Tests,
for all object classes for which the WTMD manufacturer states it can meet the
performance specifications. General guidelines and initial procedures as specified in
Sections 6.5.1 and 6.5.2 shall apply.
5.3.2
The WTMD shall be tested as specified in, Section 6.5.3, Detection Sensitivity Test.
The detector response shall be measured at all test measurement grid locations and
shall provide a positive alarm indication for each test object of the appropriate MD
Class for each allowed orientation of the test object axes with respect to the
measurement coordinate system moving at a speed of 1.0 m/s ± 0.1 m/s. The
minimum detection condition for each appropriate MD Class recorded during the
Detection Sensitivity Test shall be applied in other subsequent tests.
5.3.3
The WTMD shall be tested as specified in Section 6.5.4, Speed Test. The WTMD
shall provide a positive alarm indication for the minimum detection condition for
each appropriate MD for the test object moving at all specified scan speeds.
5.3.4
The WTMD shall be tested according to Section 6.5.5, Repeatability Test. The
WTMD shall provide a positive alarm indication without failure for the minimum
detection condition for each appropriate MD Class for the test object moving at the
specified scan speed.
5.3.5
The WTMD shall be tested as specified in Section 6.5.6, Discrimination Test. The
WTMD shall not provide a positive alarm indication for at least 20 of 25 consecutive
trials for innocuous item test objects moving at the specified scan speed.
5.3.6
The WTMD shall be tested as specified in Section 6.5.7, Alarm Indication Timing
Test, for a test object of the appropriate MD Class and its orientation according to the
minimum detection conditions as determined in Section 6.5.3. The alarm indication
shall be detected after the test object reaches the portal entry face, but before the test
object passes the midpoint of the portal. The alarm indication shall remain activated
for 1.0 sec ± 0.1 sec for each trial.
5.3.7
The WTMD shall be tested in accordance with Section 6.5.8, Throughput Rate Test,
and shall demonstrate a throughput time of no greater than 1.2 seconds. 1
5.3.8
The WTMD shall be tested in accordance with Section 6.5.9, Alarm Reset Test, and
shall demonstrate an alarm reset time of no greater than 2.0 seconds. 2
1
Time of 1.2 seconds corresponds to a rate of at least 50 clean subjects/min.
2
Time of 2.0 seconds corresponds to a rate of at least 25 metallic objects/min.
18
Walk-Through Metal Detector Standard for Public Safety
5.3.9
Zonal Detection and Object Location (optional)
5.3.9.1
The WTMD manufacturer shall declare whether or not the WTMD provides zonal
detection and object location. This feature is optional.
5.3.9.2
If the WTMD is claimed to provide zonal detection and object location, the following
requirements shall be met.
5.3.9.3
Regardless of whether the WTMD provides zonal detection and object location, the
WTMD shall comply with all other detection performance requirements of Section
5.3. The WTMD shall be tested using the test object orientation for the minimal
detection condition for each appropriate MD Class test object. The test object shall
also be tested at each of the nine specific test measurement locations.
5.3.9.4
If the WTMD is claimed to have horizontal zones, the WTMD shall meet the
following requirements: The horizontal width, xi, of each zone shall be specified,
where it indicates the horizontal zone number. X shall be calculated and recorded as
the average of the adjacent horizontal zone widths. The sum of the horizontal zone
widths (Σxi) shall equal the portal width.
5.3.9.5
If the WTMD is claimed to have vertical zones, the WTMD shall meet the following
requirements: The vertical span, yj of each zone along the z-axis shall be specified,
where j indicates the vertical zone number. Y shall be calculated and recorded as the
average of the adjacent vertical zone spans. The sum of the vertical zone spans (Σyi)
shall equal the portal height, and the portal height shall be spanned by at least three
zones.
5.3.9.6
The indication accuracy of any metallic objects of the appropriate object class shall
be ± 0.5*X in the x-axis direction and ± 0.5*Y in the z-axis direction as measured
from the geometric center of the test object for its given orientation to the geometric
center of the WTMD manufacturer-defined horizontal and vertical zones.
5.3.9.7
The WTMD shall correctly indicate the location of all test objects of the appropriate
size class by highlighting the corresponding zone. This test shall be performed a total
of five times.
5.4
WTMD Demonstration Requirements
5.4.1
The WTMD shall be tested as specified in Section 6.6, WTMD Demonstration Test,
and shall provide a positive alarm indication for the test object located within the
appropriate measurement plane for each required orientation of the test object axes
and at each required speed. The WTMD shall not provide a positive alarm indication
in the absence of the test object.
Note: The WTMD Demonstration Test is performed within several test methods of
Chapter 6 to verify proper operation of the WTMD. The above WTMD
demonstration requirements shall be met in every case.
19
Walk-Through Metal Detector Standard for Public Safety
5.5
Operator Control Requirements
5.5.1
The WTMD shall be tested as specified in Section 6.7, Operator Control Test, for the
operator control functions of power on/off and audio alarm on/off. The WTMD shall
successfully perform all functions.
5.6
Program Storage Requirements
5.6.1
The WTMD shall be tested for program and detection sensitivity settings storage as
specified in Section 6.8, Program Storage Test, and the program parameters prior to
AC power interruption shall be identical to those recorded after a 5-minute
interruption in AC power.
5.7
Alarm Indicator Requirements
5.7.1
All audible alarm indicators (excluding any earphone) shall be tested as specified in
Section 6.9, Audible Alarm Indicator Test, and shall produce an alarm-state sound
pressure level of at least 75 dB ± 5 dB at 0.8 m ± 0.08 m from the WTMD as
measured during the test. For status indicators, the audible alarm shall be a two-state
audible alarm: active (alarm state) and inactive (nonalarm state). The two-state alarm
indicator shall produce no sound in the nonalarm state.
5.7.2
Any visible alarm indication shall be tested as specified in Section 6.10, Visible
Alarm Indicator Test, and shall be readily perceptible. The visible alarm indicators
shall be a two-state visible alarm: active and inactive. The active indication shall be
illuminating, and the inactive indication shall be non-illuminating.
5.7.3
The WTMD shall be tested for metal object detection as specified in Section 6.11,
Metal Object Detection Alarm Indication Test, and shall have a two-state audible
alarm indicator and a visible alarm indicator that shall alarm to indicate the presence
of a test object in the portal region. The alarm state for the metal object detection
visible alarm indicator shall be active (illuminating) and the nonalarm state shall be
inactive (nonilluminating). The metal object detection visible alarm indicator shall be
distinct from any other visible alarm indicators.
5.8
Status Alarm Indicator Tests
5.8.1
The WTMD shall be tested as specified in Section 6.12, System Status Alarm
Indicator Test, and shall have a two-state audible alarm indicator or a visible alarm
indicator to indicate the operational state of the WTMD and shall be activated if the
operational state of the WTMD can cause a degradation of the detection performance
required by this standard. The system status visible alarm indicator shall be inactive
(nonilluminating) if the system status is acceptable and shall be active (illuminating)
if a system status problem exists. The system status visible alarm indicator shall be
distinct from any other visible alarm indicators.
20
Walk-Through Metal Detector Standard for Public Safety
5.8.2
The WTMD shall be tested as specified in Section 6.13, Detection Ready State Alarm
Indicator Test, and shall have a visible indicator showing the ready state of the
WTMD clearly visible to approaching traffic and the operator. The ready state shall
be indicated by a green and red visible indicator; the green visible indicator shall
denote readiness and the red visible indicator shall denote lack of readiness. The
green light (or Go light) shall indicate that the WTMD is ready for a person to enter
and pass through the portal, and the red light (or Stop light) shall indicate that the
WTMD is not ready for a person to enter. The WTMD shall have a two-state audible
alarm indicator or a visible alarm indicator to indicate passage of a person through
the portal when it is not in the ready state, and shall be activated if a person attempts
to pass through the portal when it is not in the ready state. The visible alarm indicator
shall be active (illuminating) if a person attempts to pass through the portal when it is
not in the ready state and inactive (nonilluminating) otherwise.
5.8.3
Optional Requirement. The WTMD shall be tested as specified in Section 6.14, Speed
Range Violation Alarm Indicator Test, and shall contain a visible alarm indicator that
is activated if the speed of a person walking through the portal is outside the speed
range of 0.2 m/s ± 0.1m/s to 2.0 m/s ± 0.1 m/s.
5.9
Metallic Interference Requirements
5.9.1
The WTMD shall be tested in accordance with Section 6.16, Test for Operation Near
a Stationary Metal Object, and shall not produce a positive alarm indication when no
test object is presented to the WTMD.
5.9.2
The WTMD shall be tested in accordance with Section 6.17, Test for Operation Near
a Steel Floor, and shall not produce a positive alarm indication when no test object is
presented to the WTMD.
5.9.3
The WTMD shall be tested in accordance with Section 6.18, Test for Operation Near
a Steel Reinforced Floor, and shall not produce a positive alarm indication when no
test object is presented to the WTMD.
5.9.4
The WTMD shall be tested in accordance with Section 6.19, Metallic Moving Object
Test. The WTMD shall not produce a positive alarm indication when operated near a
moving metal door and shall not fail to produce a positive alarm indication when a
test object is passed through the portal.
5.9.5
Requirement for MD Class 1 only. The WTMD shall be tested in accordance with
Section 6.20, Multiple Object Interference Test, and shall produce a positive alarm
indication.
5.10
Electrical Requirements
5.10.1
The WTMD shall be tested for AC power operation as specified in Section 6.15.1, AC
Power Test. While operating at power line voltages equal to ± 10% of the nominal
value and with variations in frequency ± 5% of the nominal value of 60 Hz, the
21
Walk-Through Metal Detector Standard for Public Safety
WTMD shall provide a positive alarm indication for the test object located at the nine
test measurement grid locations for each required orientation of the test object axes
and at each required speed. The WTMD shall not provide a positive alarm indication
in the absence of the test object.
5.10.2
The WTMD shall be tested for battery backup as specified in Section 6.15.2, Battery
Backup Test. The battery backup shall automatically activate in the event that AC
voltage falls below the minimum power required for operation (see Section 5.10.1)
and shall be capable of providing at least 20 minutes of uninterrupted power to a fully
functional and operational WTMD.
5.11
Mechanical Requirements for Resistance to Shock
5.11.1
The WTMD and all of its components and their interconnections shall be tested as
specified in Section 6.21 for shock and shall exhibit no observable changes.
5.12
Environmental Requirements
5.12.1
The WTMD and all of its components and their interconnections shall meet the
requirements of this section. The requirements of sections 5.2 and 5.11 shall not be
affected by the tests identified in this section.
5.12.2
The requirements given in this section shall be applied appropriately for either indoor,
sheltered outdoor or outdoor WTMD models.
5.12.3
The tests identified in this section shall be performed on the same sample.
5.12.4
The WTMD shall be tested as specified in Section 6.22, Indoor or Sheltered Outdoor
Temperature Stability and Range Test, and shall operate over an ambient temperature
range of at least 0°C to 46°C (32 F to 115°F).
5.12.5
The WTMD shall be tested as specified in Section 6.23, Outdoor Temperature
Stability and Range Test, and shall operate over an ambient temperature range of at
least -37°C to 65°C (-35°F to 149°F).
5.12.6
The WTMD shall be tested as specified in Section 6.24, Relative Humidity Stability
and Range, and shall meet or exceed the requirements of IEC 60068-2-30.
5.12.7
The WTMD shall be tested as specified in Section 6.25, Environmental Protection,
Indoor Test, and shall meet or exceed the requirements for compliance to IEC 60529
Classification IP41.
5.12.8
The WTMD shall be tested as specified in Section 6.26, Environmental Protection,
Sheltered Outdoor Test, and shall meet or exceed the requirements for compliance to
IEC 60529, Classification IP53.
22
Walk-Through Metal Detector Standard for Public Safety
5.12.9
The WTMD shall be tested as specified in Section 6.27, Environmental Protection,
Outdoor Test, and shall meet or exceed the requirements for compliance to IEC
60529, Classification IP55.
5.13
Electromagnetic Interference Requirements
5.13.1
The WTMD shall be tested for radiated emissions as specified in Section 6.28,
Radiated Emissions Test, and shall meet the requirements of Table 1 of IEC 61000-63:2006, as amended.
5.13.2
The WTMD shall be tested for conducted emissions as specified in Section 6.29,
Conducted Emissions Test, and shall meet the requirements of Table 1 of IEC 610006-3:2006, as amended.
5.13.3
While operating in a radiated magnetic field as specified in Section 6.30, Radiated
Magnetic Field Test, the WTMD shall not provide a positive alarm indication in the
absence of a test object and shall not fail to provide a positive alarm indication in the
presence of an MD Class 1 test object.
5.13.4
The WTMD shall be tested as specified in Section 6.31, Radiated RF
Electromagnetic Field Immunity Test, and shall not provide a positive alarm
indication in the absence of a test object and shall not fail to provide a positive alarm
indication in the presence of an MD Class 1 test object.
5.13.5
The WTMD shall be tested as specified in Section 6.32, 60 Hz Radiated Magnetic
Field Test, and shall not provide a positive alarm indication in the absence of a test
object and shall not fail to provide a positive alarm indication in the presence of an
MD Class 1 test object
5.13.6
The WTMD shall be tested as specified in Section 6.33, Electrostatic Discharge Test,
and shall not provide a positive alarm indication in the absence of a test object and
shall not fail to provide a positive alarm indication in the presence of an MD Class 1
test object.
5.13.7
The WTMD shall be tested as specified in Section 6.34, Fast Transients Test, and
shall not provide a positive alarm indication in the absence of a test object and shall
not fail to provide a positive alarm indication in the presence of an MD Class 1 test
object.
5.13.8
The WTMD shall be tested as specified in Section 6.35, Surges Test, and shall not
provide a positive alarm indication in the absence of a test object and shall not fail to
provide a positive alarm indication in the presence of an MD Class 1 test object.
5.13.9
The WTMD shall be tested as specified in Section 6.36, RF Common Mode, and shall
not provide a positive alarm indication in the absence of a test object and shall not fail
to provide a positive alarm indication in the presence of an MD Class 1 test object.
23
Walk-Through Metal Detector Standard for Public Safety
5.13.10
The WTMD shall be tested as specified in Section 6.37, Voltage Interruptions and
Dips Test, and shall not provide a positive alarm indication in the absence of a test
object and shall not fail to provide a positive alarm indication in the presence of an
MD Class 1 test object.
24
Walk-Through Metal Detector Standard for Public Safety
6.
TEST METHODS
6.1
General Test Requirements
6.1.1
Each test shall be performed on one sample representative of the production model.
Unless specified otherwise within a test method, the WTMD manufacturer shall
specify whether a new, untested sample is used for each test.
6.1.2
All test data and observations shall be recorded and reported.
6.2
General Test Conditions
6.2.1
Test location. The distance between any metal object other than a test object shall be
at least 32.5 cm from the detector floor, at least 50 cm from the topmost part of the
WTMD and at least 0.8 m from any side or outward projections of any side of the
WTMD.
6.2.2
Environment. All tests, except for the environmental tests, shall be performed at
conditions of 22°C ± 5°C (71.6°F ± 9.0°F), with relative humidity of 30% to 75%
noncondensing, and atmospheric pressure of 86 kPa to 106 kPa (645 mm HG to 795
mm Hg) 3 .
6.2.3
Preparations. The WTMD shall be installed according to the WTMD manufacturer’s
instructions. Any setup or calibration adjustments specified in the operator’s manual
shall be performed if required.
6.3
Test Objects and Equipment
6.3.1
Test objects. Test objects, allowed orientations and positions are provided in NIJ
Report 100-07.
6.3.2
Three-axis positioning system. The three-axis positioning system shall meet the
following requirements:
3
•
Displacement, x axis: ≥ 1 m.
•
Displacement, y axis: ≥ 1.2 m
•
Displacement, z-axis: ≥ 2 m.
•
Position accuracy, each axis: 1 mm.
•
Position repeatability, each axis: 1 mm.
ANSI N42.44-2008, American National Standard for the Performance of Checkpoint Cabinet
X-Ray Imaging Security Systems.
25
Walk-Through Metal Detector Standard for Public Safety
•
Maximum speed, y-axis: 2 m/s.
6.3.3
Magnetic field sensor. The magnetic field sensor shall have a frequency response
bandwidth at least five times greater than the bandwidth of the generated magnetic
field, shall provide a rms voltage output and shall have dimensions less than or equal
to 4 cm x 4 cm x 4 cm.
6.3.4
Voltmeter. The AC voltmeter shall have a bandwidth at least five times greater than
the bandwidth of the generated magnetic field, allow computer control and data
retrieval, and have a variable gain input with at least 10-bit resolution full scale.
6.3.5
Microphone. A microphone shall be used to detect an audible positive alarm
indication as described in Section 5.7, Alarm Indicator Requirements, and shall
provide an analog output that can be interfaced to the computer controller (see
Section 6.3.12).
6.3.6
Sound pressure level meter. A sound pressure level meter shall be used to measure
the magnitude of the audible alarm indication and shall comply with ANSI
S1.4:1983, for type 2, A-weighting, reference pressure of 20 μPa.
6.3.7
Light detector. A light detector shall be used to detect a visible positive alarm
indication as described in Section 5.7, Alarm Indicator Requirements, and shall
provide an analog electrical output that can be interfaced to the computer controller
(see Section 6.3.12). The light detector shall have a coaxial output connector and an
output impedance of ≥ 50 Ω.
6.3.8
Illumination meter. An illumination meter shall be used to measure the intensity of
the background light level and the visible alarm indication. The illumination meter
shall be capable of measuring light levels of 25 lm/m2 and 10,000 lm/m2 with an error
of not more than 10%. The integrated spectral response shall be within 10% of the
Commission Internationale de l’Eclairage photopic curve found in ISO/CIE
23539:2005.
6.3.9
Oscilloscope or waveform recorder: This device shall have at least three channels, a
sensitivity range of at least 10 mV to 10 V and a minimum bandwidth of 20 MHz.
6.3.10
Detector platform. The WTMD shall have a nonconductive, nonmagnetic platform
on which it rests. The WTMD mount locates the detector floor at a height of 32.5 cm
(12.8 in) and contains grooves or a shelf located at 10 cm (4 in) below its top surface.
6.3.11
Test object support platform. The test object support platform shall be constructed
of nonconductive, nonmagnetic materials. The purpose of this platform is to provide a
26
Walk-Through Metal Detector Standard for Public Safety
rest for the test objects at the test measurement location heights of: 80 cm ± 1 cm, 130
cm ± 1 cm and 180 cm ± 1 cm.
6.3.12
Computer controller. The computer controller shall have installed and operational
all necessary hardware and software for providing instrument control and data
acquisition.
6.3.13
Test probe. The test probe shall be a 38-turn, single-layer coil of 24 AWG copper
magnet wire wound on an air-core spool of 200 mm ± 5 mm diameter and 22 mm
width. The maximum diameter of the insulated wire shall be 0.559 mm. The leads
from the coil shall be brought together as a twisted pair with a twist pitch of
approximately 100 mm. A noninductive resistor with a power dissipation of
approximately 50 W shall be added in series with the test lead to bring the total
resistance of the resistor plus test leads plus coil to 5 Ω ± 0.25 Ω. The axis of the coil
is the line that passes through the center of the coil and is perpendicular to the plane
formed by the coil.
6.3.14
Signal generator/source. The signal generator must be capable of generating four
different sine-waves at (1) 60 Hz ± 1 Hz, (2) 15.75 kHz ± 10 Hz, (3) 40 kHz ± 10 Hz
and (4) 20 Hz ± 1 Hz with an amplitude of 15 V peak-to-peak ± 1 V into a 5 Ω load
(the test probe). The signal generator must also generate pulses with a repetition rate
of 20 Hz ± 1 Hz and a pulse width of 0.5 ms ± 0.1 ms with an amplitude of 15 V ± 1
V.
6.4
Safety Tests
6.4.1
The WTMD shall be tested for magnetic field exposure as specified in ACGIH–
0302:1996, as amended. The result of this test is a pass if the WTMD complies when
tested as specified. Observations and results shall be recorded.
6.5
Detection Performance Tests
6.5.1
General Guidelines
6.5.1.1
For WTMDs that contain more than one generator and/or sensor, the WTMD
response recorded shall be the one from which an alarm indication is derived.
6.5.1.2
If the WTMD can be adjusted to provide an alarm indication for both MD Class 1 test
objects and MD Class 2 test objects, the detection performance test shall be
performed for each object class. The detection performance shall be evaluated by the
test methods described in this section.
27
Walk-Through Metal Detector Standard for Public Safety
6.5.2
Initial Procedures
6.5.2.1
These initial procedures shall apply to all Detection Performance Tests.
6.5.3
•
Ensure that the required test equipment and components (e.g., voltmeter, alarm
indication detector and three-axis positioning system) are connected to the
computer controller and that the detection signal output connector is connected to
the voltmeter for analog signals or to the computer for digital signals.
•
Turn on the required test equipment and verify proper operation of the
measurement system.
•
Ensure that the WTMD is securely located and positioned in the measurement
coordinate system.
•
Adjust the WTMD to the appropriate sensitivity setting.
•
Select the appropriate test object and orientation from NIJ 100-07. Attach the test
object with the proper orientation to the positioning system.
•
Turn on the WTMD and ensure that its output functions properly by noting a
change in the alarm indicator detector reading and activation of the alarm
indication as a metal object is brought near the WTMD.
•
Ensure that the test object does not hit any objects while in motion.
Detection Sensitivity Test
The purpose of this test is to assess the WTMD capability to detect test objects of a
specified size and orientation at multiple locations within the portal.
6.5.3.1
Test procedure
•
The x-axis scan limits shall be 10 cm ± 0.5 cm from the inside surface of the
WTMD side.
•
Set the computer program to perform a y-axis scan of length equal to the portal
depth + 0.2 m (with a tolerance of ± 0.5 cm) and symmetric about the detector
plane. The y-axis scan speed shall be 1.0 m/s ± 0.1 m/s.
•
Set the x-axis position to its most positive limit and the z-axis position to zero and
indicate this positioning as the initial measurement location.
•
Perform a y-axis scan and do the following:
28
Walk-Through Metal Detector Standard for Public Safety
6.5.4
ƒ
Record the detection signal value(s) for each y-axis scan and report the
maximum of these values for each test measurement grid location.
ƒ
Record any positive alarm indication using the alarm indication detector as the
y-axis scan is being performed
•
Increment the x-axis in 5 cm ± 0.1 cm steps and repeat the y-axis scan
measurement for each x-axis increment until the most negative x-axis limit is
reached.
•
Increment the z-axis in 5 cm ± 0.1 cm steps while repeating the x-axis
incremented motion and the y-axis scan measurement until the z-axis positive
limit is reached.
•
This test must be repeated for each test object and its orientation as indicated in
NIJ100-07.
•
The test object, its orientation with respect to the measurement coordinate system,
and the specific test measurement grid location of this test object that provide the
smallest signal for the appropriate MD Class shall be recorded as the minimum
detection condition.
Speed Test
The purpose of this test is to assess the WTMD capability to perform effectively
when the test object is passed through the portal at a range of speeds.
6.5.4.1
Test procedure
•
Set the computer program to perform a y-axis scan of length equal to the portal
depth + 0.2 m (with a tolerance of ± 0.5 cm) and symmetric about the detector
plane at the minimum detection condition. The y-axis scan shall be performed at
four speeds:
ƒ
0.2 m/s ± 0.1 m/s.
ƒ
0.5 m/s ± 0.1 m/s.
ƒ
1.0 m/s ± 0.1 m/s.
ƒ
2.0 m/s ± 0.1 m/s.
•
Record any positive alarm indication using the alarm indication detector as each
y-axis scan is being performed.
•
The above steps shall be repeated nine times for a total of 10 trials at each scan
speed, and the results shall be recorded.
29
Walk-Through Metal Detector Standard for Public Safety
6.5.5
Repeatability Test
The purpose of this test is to assess the WTMD capability to detect each appropriate
test object every time it is passed through the portal.
6.5.5.1
The WTMD shall be tested according to Section 6.5.4, Speed Test, with the
modification that only one scan speed shall be used: 1.0 m/s ± 0.5 m/s. The WTMD
shall be tested at the minimum detection condition for each appropriate MD Class for
for 50 consecutive trials under the following conditions:
•
The delay between subsequent trials of a given test object shall be no more than 5
seconds.
•
The WTMD sensitivity shall not be readjusted between trials of a given test object
or between trials of the test objects of a given MD Class.
6.5.5.2
Observations and results shall be recorded.
6.5.6
Discrimination Test
The purpose of this test is to assess the WTMD capability to not detect innocuous test
objects
6.5.6.1
Test procedure
•
Set the computer program to perform a y-axis scan of length equal to the portal
depth + 0.2 m (with a tolerance of ± 0.5 cm) and symmetric about the detector
plane at the x-axis position of 0 cm ± 0.5 cm and z-axis position of 60 cm ± 0.5
cm. The y-axis scan speed shall be 1.0 m/s ± 0.1 m/s.
•
Attach the three-axis positioning system to the innocuous item test object holder
at the designated location on the innocuous item test object holder.
•
Perform the y-axis scan and record any positive alarm indication using the alarm
indication detector as the y-axis scan is being performed.
6.5.7
Alarm Indication Timing Test
6.5.7.1
The purpose of this test is to assess that the alarm indication is not activated until the
test object passes the portal entry face and remains activated only until the test object
passes the portal exit face.
6.5.7.2
Test procedure
•
A total of three trials shall be performed with the z-axis position of the test object
being different for each trial and as specified below:
1) 80 cm ± 0.5 cm.
30
Walk-Through Metal Detector Standard for Public Safety
2) 145 cm ± 0.5 cm.
3) 180 cm ± 0.5 cm.
6.5.8
•
Set the computer program to perform a y-axis scan of length equal to the portal
depth + 0.2 m (with a tolerance of ± 0.5 cm) symmetric about the detector plane
and at the minimum detection condition. The test object travel speed shall be set
at 1 m/s ± 0.1 m/s.
•
Trigger the waveform recorder to acquire data from the channel to which the
alarm indication detector is connected from the start of the scan to the end of the
scan. Perform the forward-going y-axis scan. Record as tenter the time at which the
test object passes the portal entry face. Record as t1 the time at which the alarm
indication is activated. Record as t2 the time at which the alarm indication ceases.
Record as texit the time at which the test object passes the portal exit face.
•
Repeat the forward-going y-axis scan changing the z-axis position of the test object.
•
Record all results and observations.
Throughput Rate Test
The purpose of this test is to assess the WTMD capability to be ready within a
specified time to detect a test object after an innocuous test object has passed through
the portal.
6.5.8.1
6.5.8.2
Initial procedures
•
Position the test object support platform so that the detector axis is parallel to and
the detector plane perpendicular to the top surface of the support platform, and the
z-axis of the detector is centered ± 1 cm in both the width and the length of the
support platform.
•
This procedure requires two test objects: (1) belt buckle innocuous test object and
(2) MD Class 1 or MD Class 2 test object, as appropriate.
Test procedure
•
Set the computer program to perform a y-axis scan of length equal to 1.4 m (with
a tolerance of ± 0.5 cm) and symmetric about the detector plane at the specified
measurement conditions.
•
Attach the belt buckle innocuous test object to the positioning system such that
the belt buckle passes through the portal first and the relative spacing of the test
objects is equal to the portal depth + 0.2 m (with a tolerance of ± 0.5 cm). Set the
x and z coordinates of the test object location to 0 cm ± 1 cm and 80 cm ± 1 cm
respectively.
31
Walk-Through Metal Detector Standard for Public Safety
6.5.9
•
Perform the forward-going y-axis scan at 1.0 m/s ± 0.1 m/s.
•
Record any positive alarm indication using the alarm indication detector as the yaxis scan is being performed, and record the time at which the y-axis scan
terminated.
•
Repeat the y-axis scan 9 times in the forward direction for a total of 10 trials.
Alarm Reset Test
The purpose of this test is to assess the WTMD capability to be ready within a
specified time to detect another test object after a first test object has been detected.
6.5.9.1
Initial procedures
•
Position the test object support platform so that the detector axis is parallel to and
the detector plane perpendicular to the top surface of the support platform, and the
z-axis of the detector is centered ± 1 cm in both the width and the length of the
support platform.
•
This procedure requires two test objects of the appropriate MD Class. These
objects are referred to within this test as “Object A” and “Object B”. The test
objects to be used for each MD Class are specified below:
ƒ
ƒ
ƒ
•
6.5.9.2
MD Class 1:
MD Class 2:
MD Class 3:
Steel handgun.
Aluminum knife.
Nonferromagnetic knife.
For a WTMD that is classified to detect multiple MD Classes simultaneously,
Object A shall be of the MD Class producing the highest detection response, and
Object B shall be of the MD Class producing the lowest detection response. For
example, if a WTMD is classified to detect MD Class 1, MD Class 2, and MD
Class 3, then Object A shall be the MD Class 1 test object, and Object B shall be
the MD Class 3 object.
Test procedure
•
Set the computer program to perform a y-axis scan of length equal to 1.4 m (with
a tolerance of ± 0.5 cm) and symmetric about the detector plane.
•
Attach the test objects to the positioning system such that Object A passes
through the portal prior to Object B and such that the relative spacing of the test
objects is equal to the portal depth + 0.2 m (with a tolerance of ± 0.5 cm). Set the
x and z coordinates of the test object location to 0 cm ± 1 cm and 80 cm ± 1 cm
respectively.
32
Walk-Through Metal Detector Standard for Public Safety
•
Perform the forward-going y-axis scan at 0.5 m/s ± 0.1 m/s.
•
Record any positive alarm indication using the alarm indication detector as the yaxis scan is being performed, and record the time at which the y-axis scan
terminated.
•
Repeat the forward-going y-axis scan nine times.
6.6
WTMD Demonstration Test
6.6.1
Initial Procedures
6.6.2
•
Ensure that the required test equipment and components (e.g., voltmeter, alarm
indication detector and three-axis positioning system) are connected to the
computer controller and that the detection signal output connector is connected to
the voltmeter for analog signals or to the computer for digital signals.
•
Turn on the required test equipment and verify proper operation of the
measurement system.
•
Ensure that the WTMD is securely located and positioned in the measurement
coordinate system.
•
Adjust the WTMD to the appropriate sensitivity setting.
•
Attach the test object of the appropriate MD Class with the proper orientation to
the positioning system.
•
Ensure that the test object does not hit any objects while in motion.
•
Turn on the WTMD and ensure that its output functions properly by noting a
change in the alarm indicator detector reading and activation of the alarm
indication as an MD Class 1 test object is passed through the portal.
Test procedure
•
Set the computer program to perform a y-axis scan of length equal to the portal
depth + 0.2 m (with a tolerance of ± 0.5 cm) and symmetric about the detector
plane at the minimum detection condition. The y-axis scan speed shall be 1.0 m/s
± 0.1 m/s.
•
Record any positive alarm indication using the alarm indication detector as the yaxis scan is being performed.
•
The test shall be performed 10 times, and the results shall be recorded.
33
Walk-Through Metal Detector Standard for Public Safety
6.7
Operator Control Test
6.7.1
The power on/off switch shall be cycled and the WTMD shall be observed to cease to
function during power off and be observed to function during power on. Functionality
shall be checked by passing an MD Class 1 test object through the WTMD and
observing an alarm indication. Observations and results shall be recorded.
6.7.2
The audible alarm shall be disabled and the WTMD shall be observed to not give an
audible alarm indication when an MD Class 1 test object is passed through. The
audible alarm shall then be enabled and the WTMD shall be observed to provide an
audible alarm indication when the same test object is passed through. Observations
and results shall be recorded.
6.8
Program Storage Test
6.8.1
Remove or disconnect the battery backup unit from the WTMD. Connect the WTMD
to AC power and switch on the WTMD. Ensure the WTMD is operating properly by
noting an alarm indication when an MD Class 1 test object is passed through the
portal. Set the WTMD to operate for a specific MD Class and record all program
parameters stored by the WTMD. Disconnect the WTMD from the AC power and
leave it disconnected for approximately 5 minutes. Reconnect the WTMD to the AC
power and turn it on. Record program parameters and compare to those parameters
recorded prior to AC power interruption.
6.9
Audible Alarm Indicator Test
6.9.1
Test Procedure
•
Perform the test in an anechoic chamber or at an outdoor location, at least 6 m (20
ft) from any large object, where the ambient sound pressure level at the time of
the test is not more than 53 dBSPL.
•
Position the sound pressure level meter microphone 0.80 m (31 in) from the
detector.
•
Measure the sound pressure level with the detector power applied and the alarm
indicator in the nonalarm state.
•
Cause the WTMD to produce an alarm and again measure the sound pressure
level.
•
Observations and the sound pressure levels shall be recorded.
34
Walk-Through Metal Detector Standard for Public Safety
6.10
Visible Alarm Indicator Test
6.10.1
Test Procedure
•
Position the WTMD with its alarm indicator 0.80 m ± 0.05 m from the eyes at a
test site where the ambient illumination is 10,000 lm/m2 ± 1000 lm/m2.
•
After waiting at least 3 minutes to allow for eye accommodation, turn on the
WTMD and move a metal object near enough to the WTMD to cause an alarm.
•
Observe the indication.
•
Repeat the test at a test site where the ambient illumination is 25 lux ± 2.5 lux.
•
Observations and results shall be recorded.
6.11
Metal Object Detection Alarm Indicator Test
6.11.1
Pass an MD Class 1 test object through the WTMD portal at a speed greater than or
equal to 0.2 m/s and less than or equal to 2.0 m/s. The test object shall pass through
the detector portal at the detector axis +/- 10 cm. The result of this test is a pass if a
positive alarm indication is obtained from both the visible and audible alarm
indicators.
6.12
System Status Alarm Indicator Test
6.12.1
The WTMD manufacturer shall provide a means to force the WTMD into a system
failure. While the WTMD is in a system failure mode, observe whether the system
status alarm is activated. Remove the failure mode and observe whether the system
status alarm is not activated. Observations and results shall be recorded.
6.13
Detection Ready State Alarm Indicator Test
6.13.1
The WTMD power shall be cycled from off to on, and it shall be observed that the
WTMD enters a ready mode by not displaying a ready state violation alarm
indication.
6.13.2
A clean tester shall carry an MD Class 1 test object through the portal. Ensure the
WTMD is operating properly by noting a positive alarm indication when the test
object passes through the portal. Also note whether the detection ready state violation
alarm indication is activated immediately after the clean tester passes through the
portal.
6.13.3
Once the alarm indication is deactivated, the clean tester shall carry an MD Class 1
test object through the portal. Again, note activation followed by deactivation of the
detection ready state violation alarm indication.
35
Walk-Through Metal Detector Standard for Public Safety
6.13.4
Observations and results shall be recorded.
6.14
Speed Range Violation Alarm Indicator Test (Optional)
6.14.1
A clean tester shall pass through the portal at a speed below 0.2 m/s ± 0.1m/s and
again above 2.0 m/s ± 0.1 m/s. The speed range violation alarm indicator shall
indicate a violation on each pass.
6.14.2
Observations and results shall be recorded.
6.15
Electrical Tests
6.15.1
AC Power Test
6.15.1.1
Connect the WTMD to an AC power source at highest rated supply voltage plus 10%
at nominal frequency and switch the WTMD on. Perform the WTMD Demonstration
Test as specified in Section 6.6. Switch the WTMD off and disconnect from the AC
power source. Observations and results shall be recorded.
6.15.1.2
Connect the WTMD to an AC power source at lowest rated supply voltage minus
10% at nominal frequency and switch on the WTMD. Perform the WTMD
Demonstration Test as specified in Section 6.6. Switch the WTMD off and disconnect
from the AC power source. Observations and results shall be recorded.
6.15.1.3
Connect the WTMD to an AC power source at nominal voltage at 5% less than the
lowest rated supply frequency and switch the WTMD on. Perform the WTMD
Demonstration Test as specified in Section 6.6. Switch the WTMD off and disconnect
from the AC power source. Observations and results shall be recorded.
6.15.1.4
Connect the WTMD to an AC power source at nominal voltage at 5% greater than the
highest rated supply frequency and switch the WTMD on. Perform the WTMD
Demonstration Test as specified in Section 6.6. Switch the WTMD off and disconnect
from the AC power source. Observations and results shall be recorded.
6.15.2
Battery Backup Test
6.15.2.1
Connect the WTMD to an AC power source at nominal voltage and switch the
WTMD on. Disconnect the AC power source so that battery backup power
automatically switches on. Perform the WTMD Demonstration Test as specified in
Section 6.6 repeatedly for 20 min ± 0.5 min.
6.15.2.2
Observations and results shall be recorded.
36
Walk-Through Metal Detector Standard for Public Safety
6.16
Test for Operation Near a Stationary Metal Object
6.16.1
Test Equipment
6.16.1.1
Metal test panel. The metal test panel shall be cold-finished sheet carbon steel AISI
C1015 to C1020 with dimensions of 1 m ± 0.01 m by 1 m ± 0.01 m by 1.25 mm ±
0.13 mm and may be mounted in a nonelectrically conductive, nonmagnetizable
frame to prevent bowing and bending of the metal test panel.
6.16.2
Test procedure.
6.16.2.1
The metal test panel shall be positioned such that its large surfaces are perpendicular
to the detector plane, the x-axis of the measurement coordinate system passes through
the center of the metal test panel and the x-axis separation between the metal test
panel and the closest surface of the WTMD is 30 cm ± 1 cm.
6.16.2.2
Any positive alarm indication shall be recorded after the panel is positioned. Perform
the WTMD Demonstration Test, as specified in Section 6.6, without moving the metal
test panel. Perform the test on both sides of the portal.
6.16.2.3
Observations and results shall be recorded.
6.16.3
A clean test subject shall walk through the center of the portal at a speed of
approximately 1.0 m/s. Any positive alarm indication using the alarm indication
detector shall be recorded as the clean test subject passes through the portal.
6.17
Test for Operation Near a Steel Floor
6.17.1
Test Equipment
6.17.1.1
Metal test panel, steel reinforced floor. The metal test panel is as described in
Section 6.16.1.1.
6.17.2
Test procedure.
6.17.2.1
Position the metal test panel such that it is parallel to and 10 cm ± 1 cm below the
detector floor, allowing the necessary time for automatic adjustment. Any positive
alarm indication after the panel is positioned shall be recorded.
6.17.2.2
Readjust the floor gain control of the WTMD, if necessary, and note the new gain
settings.
6.17.2.3
Perform the WTMD Demonstration Test, as specified in Section 6.6, without moving
the metal test panel.
6.17.2.4
Observations and results shall be recorded.
37
Walk-Through Metal Detector Standard for Public Safety
6.18
Test for Operation Near Steel Reinforced Floor
6.18.1
Test Equipment
6.18.1.1
Steel reinforced floor test panel. The test floor shall be constructed of 1.6 cm ± 0.1
cm diameter steel AISI C1015 to C1020 rod. The rod shall be arranged to form a
square grid pattern with overall dimensions of 1 m ± 0.01 m by 1 m ± 0.01 m. The
rod shall be placed on a 30 cm ± 0.01 m by 30 cm ± 0.01 m center-to-center square
grid spacing.
6.18.2
Test procedure.
6.18.2.1
Position the metal test panel such that it is parallel to and 10 cm ± 1 cm below the
detector floor (see Figure 1), allowing the necessary time for automatic adjustment.
6.18.2.2
Any positive alarm indication after the panel is positioned shall be recorded.
6.18.2.3
Readjust the floor gain control of the WTMD, if necessary, and note the new gain
settings.
6.18.2.4
Perform the WTMD Demonstration Test, as specified in Section 6.6, without moving
the metal test panel.
6.18.2.5
Observations and results shall be recorded.
6.19
Metallic Moving Object Test (Metal Door Interference Test)
6.19.1
Test Equipment
6.19.1.1
Metal test door. The metal test door shall consist of a metal plate made of coldfinished sheet carbon steel AISI C1015 to C1020 with dimensions of 2 m ± 0.02 m by
1 m ± 0.02 m by 2 mm ± 0.2 mm attached with hinges to a stationary wooden frame
such that the metal plate can swing 180° without obstruction.
6.19.2
Test procedure.
6.19.2.1
Position the metal test door such that the plane of the door is parallel to the detector
plane and the edge of the door in its closest possible position is 2 m ± 0.1 m from the
closest surface of the WTMD.
6.19.2.2
Rotate the metal test door 90° in one direction and then rotate the metal test door180°
in the opposite direction in 4 s ± 1 s.
6.19.2.3
Any positive alarm indications shall be recorded.
6.19.2.4
Rotate the metal test door back and forth as specified in Section 6.19.2.2, while
passing an appropriate MD Class test object through the portal.
38
Walk-Through Metal Detector Standard for Public Safety
6.19.2.5
Any failure to provide a positive alarm indication when the test object is passed
through the portal shall be recorded.
6.20
Multiple Object Interference Test
6.20.1
Initial Procedures
6.20.1.1
Ensure that the alarm indication detector and three-axis positioning system are
connected to the computer controller.
6.20.1.2
Turn on the alarm indication detector, the computer controller and the three-axis
positioning system and verify proper operation of the measurement system.
6.20.1.3
Ensure that the WTMD is securely located and positioned within the measurement
coordinate system.
6.20.1.4
Adjust the WTMD to the appropriate sensitivity setting.
6.20.1.5
Attach the test object with the proper orientation to the three-axis positioning system.
6.20.1.6
Turn on the WTMD and ensure that its output functions properly by noting a change
in the alarm indication detector reading as a metal object is brought near the portal
region.
6.20.1.7
Ensure that the test object does not hit any objects while in motion.
6.20.1.8
Attach the MD Class 1 steel handgun replica with Orientation 2 (see mechanical
drawing of the encased test object, NIJ Report 100-07) to the three-axis positioning
system.
6.20.1.9
Attach the MD Class 1 aluminum handgun replica (using the same orientation as that
of the steel handgun replica) to the steel handgun replica using nonelectrically
conductive nonmagnetic tape so that the aluminum handgun is to the right of the steel
handgun and making maximum physical contact.
6.20.2
Test procedure
6.20.3
Set the computer program to perform a y-axis scan of length equal to the portal depth
+ 0.2 m (with a tolerance of ± 0.5 cm) and symmetric about the detector plane. The
y-axis scan speed shall be 1.0 m/s ± 0.1 m/s, and the y-axis scan shall occur at the xaxis position of 0 cm ± 1 cm centered on the z-axis at the z-axis position of 80 cm ± 1
cm.
6.20.4
Perform the y-axis scan and record any positive alarm indication using the alarm
indication detector as the y-axis scan is being performed.
39
Walk-Through Metal Detector Standard for Public Safety
6.20.5
Repeat the y-axis scan for the z-axis position of 110 cm ± 1 cm and 130 cm ± 1 cm
and record any positive alarm indication using the alarm indication detector as the yaxis scan is being performed.
6.21
Mechanical Resistance to Shock Test
6.21.1
The WTMD shall be tested for mechanical shock in accordance with the requirements
of IEC 60068-2-27:2008, as amended, using the half-sine pulse shape with a nominal
peak acceleration of 5 g (50 m/s2) and nominal pulse duration of 30 ms. Observations
and results shall be recorded.
6.22
Indoor or Sheltered Outdoor Temperature Stability and Range Test
6.22.1
The WTMD shall be conditioned in accordance with MIL-STD-810F:2000 Method
501.4, Procedure II, at 46°C ± 3°C for 24 hours ± 1 hour. After being exposed to that
temperature continuously for 24 hours ± 1 hour, perform the WTMD Demonstration
Test, as specified in Section 6.6. The WTMD then shall be cooled to 0°C ± 3°C
within 4 hours ± 0.5 hour. After being exposed to that temperature continuously for
24 hours ± 1 hour, perform the WTMD Demonstration Test, as specified in Section
6.6.
6.23
Outdoor Temperature Stability and Range Test
6.23.1
The WTMD shall be conditioned in accordance with MIL-STD-810F:2000 Method
501.4, Procedure II, at 65°C ± 3°C for 24 hours ± 1 hour. After being exposed to that
temperature continuously for 24 hours ± 1 hour, perform the WTMD Demonstration
Test, as specified in Section 6.6. The WTMD then shall be cooled to -37 °C ± 3°C
within 4 hours ± 0.5 hour. After being exposed to that temperature continuously for
24 hours ± 1 hour, perform the WTMD Demonstration Test, as specified in Section
6.6.
6.24
Relative Humidity Stability and Range Test
6.24.1
The WTMD shall be conditioned in accordance with the requirements of IEC 600682-30, as amended. The most severe test described in IEC 60068-2-30, Section 5.2 b
shall be used: six cycles at 55˚C. The temperature transition set forth in IEC 60068-230, Section 7.3.3, Variant 2 shall be followed. After conditioning, perform the WTMD
Demonstration Test, as specified in Section 6.6.
6.25
Environmental Protection, Indoor Test
6.25.1
The WTMD shall be tested as specified in IEC 60529, Classification IP41.
6.26
Environmental Protection, Sheltered Outdoor Test
6.26.1
The WTMD shall be tested as specified in IEC 60529, Classification IP53.
40
Walk-Through Metal Detector Standard for Public Safety
6.27
Environmental Protection, Outdoor Test
6.27.1
The WTMD shall be tested as specified in IEC 60529, Classification IP55.
6.28
Radiated Emissions Test
6.28.1
The WTMD shall be tested as specified in CISPR 22:2008, Class B, as amended, for
the frequency ranges and limits given in Table 1 of IEC 61000-6-3:2006, as amended.
Observations and results shall be recorded.
6.29
Conducted Emissions Test
6.29.1
The WTMD shall be tested as specified in CISPR 22:2008, Class B, as amended, for
the frequency ranges and limits given in Table 1 for the AC Mains Port of IEC
61000-6-3:2006, as amended. Observations and results shall be recorded.
6.29.2
The WTMD shall be tested as specified in CISPR 22:2008, Class B, as amended, for
the frequency ranges and limits given in Table 1 for the Signal, Control, DC Power
Input or Output Ports of IEC 61000-6-3:2006, as amended. Observations and results
shall be recorded.
6.30
Radiated Magnetic Field Test (Low-Frequency Magnetic Field Susceptibility
Test)
6.30.1.1
Place the WTMD on the detector platform and mark on the detector platform (and
surrounding area, depending on the size of the detector platform) three lines that are
parallel to the detector plane and the detector floor. Locate these lines so that the
middle line is coplanar with the detector plane and the other two lines are on opposite
sides of this middle line and separated from the middle line by 30 cm ± 1 cm.
6.30.1.2
Ensure that the test probe (see Section 6.3.13) is oriented so that its axis is parallel to
the detector plane and detector floor with a tolerance of 5°.
6.30.1.3
Program the signal source to provide the 60 Hz signal described in Section 6.3.14 and
connect the test probe to the signal source. Ensure that the probe is being excited by
the signal source by placing a second and similarly constructed probe next to the test
probe. Connect the second test probe to an oscilloscope or spectrum analyzer and
verify the test probe is receiving a signal from the signal source.
6.30.1.4
Position the test probe so that its axis is coplanar to within 1 cm with the leftmost
marked line, 10 cm ± 1 cm above the detector floor and 2 m ± 10 cm from the outer
surface of the WTMD.
6.30.1.5
Move the test probe toward the WTMD at a speed of 0.2 m/s ± 0.1 m/s while
changing its vertical position or coplanarity by no more than 1 cm and record the
distance, di, from the WTMD, at which the WTMD provides a positive alarm
indication.
41
Walk-Through Metal Detector Standard for Public Safety
6.30.1.6
Repeat Section 6.30.1.5 four additional times.
6.30.1.7
Record the average position, d l ,10 , for the leftmost line using Equation 1:
Equation 1: Average position.
5
d l ,10 = ∑ d l ,i ,
i =1
where the l subscript refers to the leftmost line.
6.30.1.8
Repeat sections 6.30.1.4 through 6.30.1.7 except with the test probe axis is at a height
above the detector floor of 100 cm ± 10 cm and obtain the average position, d l ,100 , at
a height of 100 cm ± 10 cm, at which the WTMD provides a positive alarm
indication.
6.30.1.9
Repeat sections 6.30.1.4 through 6.30.1.7 except with the test probe at a height above
the detector floor of 200 cm ± 10 cm and obtain the average position, d l , 200 , at a
height of 200 cm ± 10 cm, at which the WTMD provides a positive alarm indication.
6.30.1.10 Repeat sections 6.30.1.4 through 6.30.1.7 except with the test probe axis aligned with
the middle line but at a height of 10 cm ± 1 cm and obtain the average position, d m ,10 ,
at which the WTMD provides a positive alarm indication.
6.30.1.11 Repeat sections 6.30.1.8 through 6.30.1.9 except with the test probe axis aligned with
the middle line and obtain the average position, d m ,100 , at a height of 100 cm ± 10 cm,
at which the WTMD provides a positive alarm indication, and the average
position, d m , 200 , at a height of 200 cm ± 10 cm, at which the WTMD provides a
positive alarm indication.
6.30.2
Repeat sections 6.30.1.10 and 6.30.1.11 except with the test probe located at the
rightmost line and obtain the average position, d r ,10 , at a height of 10 cm ± 1 cm, at
which the WTMD provides a positive alarm indication; the average position, d r ,100 , at
a height of 100 cm ± 10 cm, at which the WTMD provides a positive alarm
indication; and the average position, d r , 200 , at a height of 200 cm ± 10 cm, at which
the WTMD provides a positive alarm indication.
6.30.3
Repeat sections 6.30.1.4 through 6.30.1.7, except with the test probe axis aligned
perpendicular to the middle line but at a height of 200 cm ± 1 cm and obtain the
average position, d c , 200 , at which the WTMD provides a positive alarm indication.
6.30.4
Program the signal source to provide the 15.75 kHz signal described in Section 6.3.14
and connect the test probe to the signal source. Ensure that the probe is being excited
42
Walk-Through Metal Detector Standard for Public Safety
by the signal source by placing a second and similarly constructed probe next to the
test probe. Connect the second test probe to an oscilloscope or spectrum analyzer and
verify the test probe is receiving the signal transmitted from the signal source. Repeat
sections 6.30.1.4 through 6.30.3.
6.30.5
Program the signal source to provide the 40 kHz signal described in Section 6.3.14
and connect the test probe to the signal source. Ensure that the probe is being excited
by the signal source by placing a second and similarly constructed probe next to the
test probe. Connect the second test probe to an oscilloscope or spectrum analyzer and
verify the test probe is receiving the signal transmitted from the signal source. Repeat
sections 6.30.1.4 through 6.30.3.
6.30.6
Program the signal source to provide the 20 Hz pulse signal described in Section
6.3.14 and connect the test probe to the signal source. Ensure that the probe is being
excited by the signal source by placing a second and similarly constructed probe next
to the test probe. Connect the second test probe to an oscilloscope or spectrum
analyzer and verify the test probe is receiving the signal transmitted from the signal
source. Repeat sections 6.30.1.4 through 6.30.3.
6.31
Radiated RF Electromagnetic Field Immunity Test
6.31.1
The WTMD shall be tested as specified in IEC 61000-4-3:2008, as amended, for
Level 2 (3V/m), for the requirements given in Table 1, Entry 1.2, of IEC 61000-61:2005, as amended. Observations and results shall be recorded.
6.32
60 Hz Radiated Magnetic Field Test
6.32.1
The WTMD shall be tested as specified in IEC 61000-4-8:2001, as amended, for
testing at 60 Hz, Level 2 (3A/m), and continuous exposure for 30 min ± 5 min for the
requirements given in Table 1, Entry 1.1, of IEC 61000-6-1:2005, as amended.
Observations and results shall be recorded.
6.33
Electrostatic Discharge Test
6.33.1
The WTMD shall be tested as specified in IEC 61000-4-2:2001, as amended, for the
requirements given in Table 1, Entry 1.5, of IEC 61000-6-1:2005, as amended.
Observations and results shall be recorded.
6.34
Fast Transients Test
6.34.1
The WTMD shall be tested as specified in IEC 61000-4-4:2004, as amended, for the
requirements given in Table 2, Entry 2.2; Table 3, Entry 3.3; and Table 4, Entry 4.5,
of IEC 61000-6-1:2005, as amended. Observations and results shall be recorded.
43
Walk-Through Metal Detector Standard for Public Safety
6.35
Surge Test
6.35.1
The WTMD shall be tested as specified in IEC 61000-4-5:2005, as amended, for the
requirements given in Table 3, Entry 3.2 and Table 4, Entry 4.4, of IEC 61000-61:2005, as amended. Observations and results shall be recorded.
6.36
RF Common Mode Test
6.36.1
The WTMD shall be tested as specified in IEC 61000-4-6:2006, as amended, for the
requirements given in Table 2, Entry 2.1; Table 3, Entry 3.1; and Table 4, Entry 4.1,
of IEC 61000-6-1:2005, as amended. Observations and results shall be recorded.
6.37
Voltage Interruptions and Dips Test
6.37.1
The WTMD shall be tested as specified in IEC 61000-4-11:2004, as amended, for the
requirements given in Table 4, entries 4.2 and 4.3, of IEC 61000-6-1:2005, as
amended. Observations and results shall be recorded.
44
Walk-Through Metal Detector Standard for Public Safety
7.
LABELING AND INFORMATION
7.1
General Product Label Requirements
7.1.1
The WTMD shall have product labels permanently and visibly attached to, stamped
on or printed on the WTMD.
7.1.2
All text on the required product label shall be at least in English.
7.1.3
At least the following information shall also be printed legibly on the product label(s)
in letters at least 3.2 mm (0.125 in) high:
•
Legal name of the WTMD manufacturer and phone number or email address.
•
Model, style and serial number.
•
MD Class(es).
•
Date of manufacture.
•
Intended operating environment (indoor, sheltered outdoor or outdoor).
•
Power requirements.
7.2
User Information to Be Provided by the Manufacturer of the WTMD
7.2.1
The WTMD manufacturer shall provide user information including, but not limited
to, warnings, information and instructions with each WTMD.
7.2.2
The WTMD manufacturer shall provide at least the following user information with
each WTMD:
•
MD Class and intended operating environment.
•
Description of controls and adjustments.
•
Description of detection principles and WTMD capabilities.
•
List of operating features.
•
Instructions for proper use and installation as intended by the WTMD
manufacturer, including placement and safety considerations.
•
Technical specifications containing, at a minimum, the following information:
o Each class for which the WTMD qualifies.
o WTMD dimensions and weight.
o Operating ambient temperature range.
o Battery backup operational time.
•
Calibration instructions.
•
Field test and performance verification procedures.
•
Warranty information.
•
WTMD manufacturer contact information, including address of
45
Walk-Through Metal Detector Standard for Public Safety
manufacturing location (city, state/province, country) and phone number.
•
7.2.3
4
Care and maintenance 4 instructions, including guidelines for inspection,
proper storage recommendations, and a detailed list of the technical skills,
computer hardware and software tools required.
The WTMD manufacturer shall have available a training package that will provide
operators with the information necessary to acquire the technical and operational
skills required to conduct effective screening with the device.
See definitions for care and maintenance in Chapter 3.
46
Walk-Through Metal Detector Standard for Public Safety
APPENDIX: Innocuous Item Test Objects
MD Class 1 Innocuous Item Test Objects. The innocuous item test objects for the MD Class 1
are a set of coins and replicas of a set of coins, a belt buckle, eyeglasses and a watch.
•
Set of coins. The set of coins shall consist of two each of U.S. pennies, nickels, dimes and
quarters minted between the years 1990 and 2000.
•
Belt buckle. The replica of the belt buckle shall be a continuous circle made from a rod of
stainless steel, classification UNS S30400, with the rod having a diameter of 6.4 mm ± 0.4
mm, and the circle an inside diameter of 50 mm ± 5 mm.
•
Eyeglasses. Figure 5 provides the mechanical drawings for the eyeglasses replica.
•
Watch. The watch replica shall be made from a disc-shaped object with the following
properties:
•
Diameter:
30 mm ± 5 mm
•
Thickness:
5 mm ± 1 mm
•
Material:
UNS S30400
MD Class 2 Innocuous Item Test Objects. The innocuous item test objects for the MD Class 2
are replicas of eyeglasses (see Figure 5) and a belt buckle. The belt buckle shall be a continuous
circle made from a rod of stainless steel, classification UNS S30400, with the rod having a
diameter of 3.0 mm ± 0.4 mm, and the circle an inside diameter of 30 mm ± 5 mm.
MD Class 3 Innocuous Item Test Objects. There are no innocuous item test objects for the MD
Class 3.
Innocuous item test object holder. Figure 6 shows the location of the innocuous item test
objects on the innocuous item test object holder and the subsequent mechanical drawings are of
the parts of the innocuous item test object holder and its assembly (to be added). All components
of the holder shall be constructed of nonelectrically conductive and nonmagnetic materials.
47
Walk-Through Metal Detector Standard for Public Safety
Figure 5. Mechanical Drawing of Eyeglass Replica
NATIONAL INSTITUTE
OF
STANDARDS AND TECHNOLOGY
48
Walk-Through Metal Detector Standard for Public Safety
Figure 6: Innocuous Item Test Object Locations.
49