A M E R I C A N C O U N C I L OF I N D E PE N D E NT L A B OR A TOR I E S
EMC Standards Alert
Premier Edition Vol. 1 No. 1
Timely Updates on
Critical Standards
Edited by
Don Heirman,
Chair,
CISPR & ANSI ASC C63®
In this issue
CISPR Activity
Basic Instrumentation
 ANSI ASC C63® Activity
 IEC activity
 EMC Standards Meetings
of Interest
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August 2009
CISPR
Basic measurement procedures, test instrumentation, and measurement
uncertainty standards are in the CISPR 16-x-y series of standards. Standards Alert
in future editions will highlight the many changes to CISPR 16-x-y Standards under
development to indicate the impact that these changes will have to test lab operations
and budgets. As an example, one of the CISPR product committees that covers
compliance measurements of industrial, scientific and medical equipment has introduced in its 2009 edition of CISPR 11 the full implementation of CISPR 16-4-2 on
measurement instrumentation uncertainty. This goes beyond simply calculating
measurement uncertainty (MU). It now indicates how MU is to be used in modifying the actual measurement result, which is then compared to the emission limit/s.
The next edition of Standards Alert will provide more information on the application
of MU as expressed in CISPR 16-4-2. The important point to note is that under certain conditions simply having a measured result under the limit may not be a pass
when MU is taken into consideration. This obviously greatly affects the test laboratory’s relationship with its customers, especially if an initial “pass” emission becomes a “fail” by taking into account MU.
Basic Instrumentation Preferred antennas are those that have the lowest uncertainties of its characteristics including its calibration. For the frequency range 30
to 1000 MHz, the lowest uncertainty antennas are bi-conicals and log periodic arrays. Combination antennas for the entire frequency range are NOT the antenna
with the lowest uncertainty. Thus, the impact in using a combination antenna is that
the measurement uncertainty will be higher than using separate antennas over partial
frequency ranges, e.g., those covered by the use of bi-conicals and log periodic arrays. So the impact for the test laboratory is to decide which is better, i.e., decrease
the test time using the combination antenna or to use antennas that decrease the
measurement instrumentation uncertainty. Note that the customer will see the measurement instrumentation uncertainty in the CISPR 22 test report and could compare
these values among test laboratories they use as they look for those with the lowest
uncertainty.
ANSI ASC C63® Activity Testing unlicensed wireless devices has been made
easier with ASC C63® publication C63.10. The standard is due to be published in
mid September. For the testing laboratories, it will be a real assistance as it assembles in one place from many scattered resources the information that the FCC uses
Join ACIL and the Conformity Assessment Section
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A M E R I C A N C O U N C I L OF I N D E PE N D E NT L A B OR A TOR I E S
ANSI ASC C63® Activity (continued)
in assessing what test applies to which device and how it is to
be conducted. This will also help in dealing with laboratory
assessments as now there is single document to review for
unlicensed wireless device testing competency.
The standard includes tests for:
 Remote control and security unlicensed wireless devices
 Freq. hopping & direct sequence spread spectrum devices
 Anti-pilferage devices
 Cordless telephones
 Radio frequency identification (RFID) tag readers
 Unlicensed National Information Infrastructure devices
 Intrusion detectors
 Unlicensed wireless devices operating below 30 MHz
 Wireless (garage) door openers
 Ultra-wideband (UWB) devices
 Automatic vehicle identification systems
 Other devices authorized under Part 15 of the FCC Rules
and Regulations (47 CFR Part 15)
2009 edition of ANSI C63.4 about to be published
The premiere emission testing standard C63.4 is now updated
since last published in 2003. Many changes were discussed
and introduced into the standard. Here are the key changes:
● For LISN calibration, tables added with the exact values of
impedance and insertion loss as a function of frequency and
clearer methods of calibration with modern instrumentation
● A new flow chart indicating what should be displayed on
PC monitors depending on the content that is normally viewed
in actual use. It extends beyond the scrolling “H” typically
used. It also applies to large screen displays as well as video
projection systems
● How to take into account antenna cable impedance changes
as a function of ambient temperature applicable when testing
at an open area test site not all weather protected
● Added a major informative annex describing precautions in
using spectrum analyzers
● Added method to take into account the impact of table top
material on emission measurements in the frequency range 30
to 1000 MHz
● Added alternative methods for site validation above 1 GHz
● After considerable discussion and the desire of the voting
members of ASC C63®, the method of measuring emissions
above 1 GHz remains the same as that in the 2003 edition
● Only allowing antenna calibration using the latest edition
of ANSI C63.5 which is 2006
● Not needed informative step by step measurement procedures contained in the annex in the 2003 edition removed as
the normative requirements are in the body of the standard.
These changes will definitely impact testing and the test laboratories that will have to accommodate the requirements in the
standard as soon as the FCC references the 2009 edition.
They also may indicate that the new standard may be used as
well as the present 2003 edition. ASC C63® has already requested the FCC to use the new edition as soon as practical.
Ordering information for C63.10 and C63.4 will be covered
in a subsequent newsletter.
IEC Activity The use of test techniques not broadly used
for commercial products are those involving the use of reverberation chambers and wide band TEM devices. Reverberation techniques have been used by the US military and automotive industries for many years. TEM use has been limited
mainly to design EMC checks by manufacturers. The standards that apply are IEC 61000-4-20 (TEM) and 61000-4-21
(Reverberation). These are capable of measuring radiated
emissions from products as well as determining the immunity
to the RF environment via a radiated immunity measurement
to test levels determined as needed by the manufacturer. In
the European Union, the EMC Directive requires showing or
stating product compliance with the EMC essential requirements for both emissions and immunity (typically 3 V/m or 10
V/m).
Immunity requirements do not exist in the US as this is considered a product quality issue that is up to the manufacturer
to set to avoid customer complaints in general when used in
the field. The impact to testing organizations is to determine
if there is a business case to use these two methods of measurement and test facilities as they start to infiltrate product
testing requirements. The most promising in cutting down test
time appears to be using reverberation technology, realizing
that reverberation in general works above 200 MHz where
there are sufficient modes to be stirred.
Upcoming Meetings
ANSI ASC C63® October 22, 2009, NIST Boulder, CO
http://www.c63.org/upcomingmeetingschedule.htm
CISPR Annual Meeting September 21-October 1, 2009,
Lyon, France
http://www.iec.ch/zone/emc/emc_cis.htm
ACIL 72nd Annual meeting October 24-26, 2009,
Gaylord Opryland Resort, Nashville, TN www.acil.org
In the next edition:
● Further explanation of use of MU in product compliance
● Review and impact of changes in selective standards including immunity standards
● Review of major components in the draft of CISPR 32,
which replaces CISPR 13 and CISPR 2
The information contained in this newsletter is current based on sources as of the date of electronic publication, is the sole opinion of its editor, Don Heirman. ACIL
is not responsible for its content.
Copyright © ACIL 2009