3/28/02
THE
THE
TNT Jan 02
7:35 AM
Page 5
NDT TECHNICIAN
A Quarterly Publication for the NDT Practitioner
TNT Focus:
Ultraviolet Safety
Ultraviolet radiation used in
nondestructive testing is obtained by
filtering hard ultraviolet radiation out
of radiation produced by a high
intensity discharge lamp. Because the
light fixture uses electric current,
electric shock is a very real hazard.
Heat generated by the light is also
capable of
inflicting severe
burns as well as
causing
flammable liquids
used in some of
the NDT methods
to ignite if the
light is not used
properly. NDT
technicians
should keep in
Shannon Luminous Materials, Inc. Santa Ana, CA
mind that several
cleaner/removers
are classified as Class 3 flammable
substances, and some aerosol
developers are Class 4. For
comparison, gasoline is a Class 3
flammable liquid.
Another, but much less obvious,
danger is the effect of ultraviolet
radiation on the operator. Ultraviolet
radiation used for inspection work,
improperly referred to as “blacklight,”
has wavelengths from 320 to 400 nm
(the edge of the visible spectrum) and
is referred to as near ultraviolet or
ultraviolet-A or long wave ultraviolet
radiation. These ultraviolet-A
wavelengths are those used for NDT.
Ultraviolet radiation is commonly
Volume 1, Number 1
TNT Tip: Device to Hold Hot
UV Lamps
measured in microwatt per square
centimeter (µW/cm2), the power
(microwatt) falling on one square
centimeter (0.155 in.2) of surface area.
At higher irradiance levels, the watt
per square meter (W/m2) is used
(100 µW/cm2 = 1 W/m2).
The 365 nm near ultraviolet
wavelength is well out of the range
where physiological effects take place,
and the effects such as damage to the
eye, sunburn and destruction of tissue
do not come into evidence until
wavelengths are reduced to the
neighborhood of 320 nm. Here they
become definitely injurious. The
wavelengths from 280 to 320 nm are
known as ultraviolet-B, midwave or
erythemal ultraviolet, so named for its
reddening effect on skin. Ultraviolet-B
wavelengths can cause sunburn and
snow blindness, and are not used for
nondestructive testing. Both
ultraviolet-B and ultraviolet-C
radiation (wavelengths from 100 to
280 nm) are very hazardous and can
cause severe skin and eye damage after
very short exposure.
Proper operation of the ultraviolet
lamp used in NDT is essential to good
testing and to operator comfort and
efficiency. If an ultraviolet lamp
becomes damaged, UV radiation with
wavelengths shorter than 310 nm may
escape its protective enclosures or
filters. Operator exposure to this short
wavelength radiation may cause a
condition known as photokeratitis
continued on page 2
January 2002
TNT Focus: Ultraviolet Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TNT Tip: Device to Hold Hot UV Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tech Toon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TNT Practitioner Profile: Ricky L. Morgan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
1
2
4
Holding a hot UV light at the required
distance to accurately measure output is
difficult, especially if there are several
lamps and various specifications to meet.
We have four working black lamps in our
lab — the type with a woods filter and
retaining ring. Each must be measured for
output at monthly intervals to meet
national standards and client
specifications such as:
■
■
■
800 µW/cm2 @ 400 mm
1,000 µW/cm2 @ 380 mm, 400 mm,
and the working distance
500 µW/cm2 @ 460 mm
Different methods to hold the lamps
were tried. Retort stands and clamps,
sticky tape, and sky hooks couldn’t
reliably reproduce the test situation for
measuring output.
Here’s a fix. This simple and easily
made device can:
■
■
■
hold the lamp at the required distance,
be used at various distances, and
reliably reproduce the setup for
measurement on a regular basis.
It can also be used for different types of
lamps including new air-cooled units.
Materials:
■ coffee can - 1 kg size with 6 in.
(150 mm) rim
■ plywood base - 14 × 14 × 2 in. (350 ×
350 × 50 mm)
■ hardwood upright - 2 × 2 × 19 in.
(50 × 50 × 500 mm)
■ 3 No. 8 countersunk woodscrews - 4 in.
(100 mm)
■ 2 No. 8 roundhead woodscrews - 1 in.
(25 mm)
■ matte black paint - 0.5 pint (200 mL)
■ wood of varying thicknesses for shims
continued on page 2
TNT Jan 02
3/28/02
7:35 AM
Page 2
■ THE NDT TECHNICIAN
Tech Toon
TNT Tip: Continued from page 1
Safety Precautions
followed by conjunctivitis, similar to
snowblindness. Symptoms may progress from a
feeling of sand in the eyes, allergy to light, tear
formation and temporary blindness. These
symptoms usually begin 6 to 12 h after exposure
and last for 6 to 24 h, with symptoms usually
disappearing in 48 h. Because of this, it is essential
that the ultraviolet lamp not be used unless the
proper filter is in place and is not damaged.
The major safety precautions for
ultraviolet radiation sources then are
as follows.
THE
TNT Focus: continued from page 1
NDT TECHNICIAN
A Quarterly Publication for the NDT Practitioner
Volume 1, Number 1
January 2002
Publisher : Thom Passek
Publications Manager : Paul McIntire
Editor : Hollis Humphries
Technical Editor : Ricky L. Morgan
Review Board: William W. Briody, Ed E. Edgerton,
Anthony J. Gatti Sr., Jesse M. Granillo, Edward E. Hall,
Richard A. Harrison, James W. Houf, Raymond G.
Morasse, Ronald T. Nisbet
The NDT Technician: A Quarterly Publication for the NDT
Practitioner (ISSN 1537-5919) is published quarterly by the
American Society for Nondestructive Testing, Inc.
The NDT Technician: A Quarterly Publication for the NDT
Practitioner, 1711 Arlingate Lane, PO Box 28518, Columbus, OH
43228-0518. ASNT is not responsible for the authenticity or
accuracy of information herein and published opinions and
statements do not necessarily reflect the opinion of ASNT. Products
and/or services that are advertised or mentioned do not carry the
endorsement or recommendation of ASNT. Copyright © 2001 by
the American Society for Nondestructive Testing, Inc. All rights
reserved. Printed in the United States of America.
2
1. Eliminate the direct irradiation of
the unprotected hand when
manipulating small test objects. If
an inspector’s hands are subject to
5000 µW/cm2, then the
recommended daily ultraviolet-A
exposure can be exceeded in 200s.
2. Eliminate accidental direct
viewing of, and dermal exposure
to, lamps used in other testing
stations, lamps permanently
mounted in the same booth and
those being used by other
inspectors in the same area.
Lamps using a 100 W bulb have
increased potential for
unintentional hand irradiation
because of larger spot area.
Unintentional viewing can occur
easily as inspectors move around
within the testing area.Varying or
multiple source heights increase the
possibility of direct exposure to
ultraviolet radiation. The use of suitable
gloves, protective ultraviolet absorbing
eyewear and opaque or closely woven
clothing to cover potentially exposed
dermal areas should be recommended to
personnel operating in such situations.
Good evidence now indicates that
near ultraviolet radiation can be
hazardous if allowed to fall on the eyes or
Procedure:
1. Set lamp in holder.
2. Allow lamp to warm up for 20 min.
3. Place light meter on baseboard in
center of cross.
4. Vary distance with shims.
5. Record output of lamp.
Reviewer’s Note: There is a slight
increase in the reading when using
the can (which has 14 corrugations).
A borderline call might be best
checked without the lamp holder.
Con Murren
Ayrshire, Scotland
UV Lamp
Can
centered
over
base
Stem
SHOULD HAVE MENTIONED YOU HAD BRACES.”
19.7 in.
(500 mm)
“YOU
Method:
1. Remove base from coffee can and
smooth down rough or sharp edges
left by can opener.
2. Using three large screws, attach
upright to base as shown in sketch.
3. Attach can to stem as shown using
two small screws.
4. Paint complete unit, including inside
of can, with matte black paint.
5. Project vertical centerline of can
down to base and mark a cross.
6. Cut wood shims of different
thicknesses to alter distance between
baseboard and base of lamp.
Coffee can
Base
3.9 in.
(100 mm)
9.8 in.
(250 mm)
Base
13.8 in.
(350 mm)
Device to hold hot UV lamps.
skin without limit. These effects vary in
severity, depending on the extent of
exposure over time. In the past,
ultraviolet radiation damage was
popularly associated with irradiation of
the body at wavelengths shorter than
320 nm.Although erythemological
efficiency may be 200 to 2000 times
higher at shorter wavelengths, animal
TNT Jan 02
3/28/02
7:35 AM
Page 3
Ultraviolet Safety ■
Volume 1, Number 1
studies show that damaging effects also can
occur from long exposures at ultraviolet-A
wavelengths.
Ocular Fluorescence from Long
Wavelength Ultraviolet
Radiation
Long wavelength ultraviolet radiation is a
natural component of the environment;
Earth’s atmosphere does not completely filter
out the ultraviolet radiation emitted by the
sun. Regardless of the source, natural or
artificial, ultraviolet radiation can cause
human eye media to fluoresce. This in turn
produces uncomfortable sensations, irritation
or pressure, especially in low visible light
levels. Ocular fluorescence is temporary but
can be eliminated entirely by using ultraviolet
absorbing eyewear. In some cases, such
eyewear can actually increase the contrast
(reduce ambient background levels) and
thereby improve the sensitivity of fluorescent
tests because the ocular fluorescence will
enhance the visual acuity of the inspector.
Long wavelength ultraviolet radiation is
considered relatively harmless when compared
to other parts of the ultraviolet spectrum. In a
few cases, permanent histological changes have
been reported. Note also that abnormally high
sensitivities can be produced by certain drugs
and chemicals. People exposed to these
sensitizing agents or individuals who are
particularly photosensitive should expect
adverse reactions to long wavelength ultraviolet
radiation. However, it is unusual for symptoms
of photosensitization to be elicited solely by the
limited emission spectrum of lamps used in
fluorescent liquid penetrant tests.
Summary of Ultraviolet
Radiation Safety
With appropriate precautions, fluorescent
NDT can be performed safely and effectively.
General rules of ultraviolet safety are designed
to protect those who may be exposed to such
radiation, directly or accidentally.
The first level of protection includes
posting areas where ultraviolet radiation exists
Did you know that ...
... you could use an adjustable wrench to pull nails?
Close the jaws, slip the slot at the back of the wrench over the head of an exposed
nail, then rotate the wrench forward over the closed jaws to pull the nail.
... you could retrofit a 10 in. adjustable wrench to fit the head of a standard 3/4 in.
A-325 bolt?
Remove the sliding jaw from the wrench, then use the edge of a thin grinding
wheel to add one additional slot to the front of the adjustment rack. The jaws will
then open wide enough to fit the 1-1/4 in. flats of the bolt.
in excess of safe limits. Legal signage must
display standard caution - ultraviolet radiation
warnings and may contain additional health
protection information. Color and size of such
signs should meet Federal and state
requirements (see 29 CFR 1910.115).
Control of the environment is another
critical safety measure. Equipment that
produces ultraviolet radiation should be
enclosed by partitions, screens or walls
painted with nonreflective paint. Paint
containing metallic particles should not be
used. In addition, equipment must be labeled
to inform individuals of potential health and
safety hazards. Contact the Occupational
Safety and Health Administration (OSHA),
the American National Standards Institute
(ANSI), the American Conference of
Governmental Industrial Hygienists (ACGIH)
and the National Institute for Occupational
Safety and Health (NIOSH) to learn more
about the environmental requirements.■
Parts of this feature adapted from the Nondestructive Testing
Handbook, third edition: Volume 2, Liquid Penetrant Testing and
Materials Evaluation, Vol. 54, No. 3. Contact the editor for more
information.
Join Our Fan Club!
Super-High Intensity, Fan-Cooled UV Lamps!
View critical indications with unmatched accuracy!
Special thanks to Jim Houf, ASNT Technical Services Manager
Both lamps feature:
The world’s only
fan-cooled, 150-watt,
self-ballasted lamp!
7,000µW/cm2 at 15”
• Reduced running temperatures —
provide maximum safety and comfort
FROM THE EDITOR:
The TNT mission is “to provide information valuable to NDT
practitioners and a platform for discussion of issues relevant to their
profession.”
Simply put, we’d like this newsletter to be of use to you as an NDT
practitioner. TNT would also like to reflect your participation.We need
your input. If you are an NDT contractor and want to take advantage of
some free advertising, send us your contact info and NDT methods you
use. It will be published here in our contractor database and on our Web
page.We also want to ensure that our content is relevant to your NDT
practice. Let us know the information you want.We’ll do the rest. Got a
tip that makes the practitioner’s job easier? Send it along too. This is a
great opportunity to put your ideas into print. Contact us at ASNT.
Hollis Humphries
TNT Editor
tnt@asnt.org: (800) 222-2768 (X206): fax (614) 274-6899
• Performance that meets MIL and
ASTM specifications for FPI and MPI
• Tough polymer lamp housing,
lightweight lamp head, comfortable
pistol-grip handle
Additional features
of FC-150:
• 3-position rocker switch
— off / fan-only / fan and lamp on
• 150-watt Built-In-Ballast™ bulb
produces the power of competitive
transformer-based lamps without a
heavy transformer.
FC-150
Fan-cooled,
100-watt, transformerbased lamp!
7,500µW/cm2 at 15”
FC-100
For more information,
call
1-800-274-8888
and ask for a Customer
Service Representative
3
TNT Jan 02
3/28/02
7:35 AM
Page 4
■ THE NDT TECHNICIAN
TNT Practitioner Profile:
Ricky L. Morgan
Ricky’s been a member of
ASNT since 1990. He’s
Director for Region 15, active
in the Section Operations
Council (SOC) and has served
the Greater Los Angeles
section. On a personal note, he
rides dirt bikes, an all-terrain skateboard and is a
national champion powerlifter.And by the way, he’s
the new Technical Editor for this publication, TNT.
Ricky, how did you become a practitioner in
NDT?
Initially, I got involved in NDT at the College
of Oceaneering in Wilmington, CA. In order to
back myself up for future career opportunities, I
took the program for underwater NDT at the
same time. I figured that would be a good
background for something I could do on land as I
got older and less adventurous. I still do basically
the same things I learned back then except now
I’m applying them to buildings.
What is the most unusual application of NDT
you’ve done?
I’ve done some dye penetrant testing on
windmills in the Palm Springs area. Basically, a
windmill is a big propeller and we were checking
to see if there was cracking on the leading edges.
I’ve also done a lot of work on amusement park
rides in this area.
Have you ever talked to someone outside of
NDT who knew what NDT was and how do
you explain it to them if they don’t?
I think, generally, no.You kind of have to
have an engineering background. People usually
don’t have a very good grasp of what we do. To
explain it to them, I usually go to a medical
analogy. Everybody has had an X-ray or
ultrasound.You can look at the X-ray or
ultrasound of a break in a bone.We do the same
thing but we look at a weld in steel.
What’s the worst part of NDT?
It would probably be the feeling that you are
the necessary evil. It’s required but most of the
time they don’t really want you there. Most
construction companies would rather do it all
on their own and not have someone looking
over their shoulder. To them, you are kind of the
bad guy.
So you are really kind of like a detective. If
there is a problem, are you going to have to
find it by yourself?
Yes, you have to do a little bit of investigation
on your own.You can’t always rely on all the
information you are given.
How do you think the practitioner is
perceived?
Actually, the practitioner or technician is
considered an intermediate level between
engineering and production. Kind of in the
middle between the two. To some extent, you’re
like a liaison. Inside the NDT community it’s
understood that you have to have a certain
amount of knowledge to do any kind of testing.
What’s the best part of NDT?
I think the best part is knowing when you
have finished a project that you’ve built a quality
TNT Inbox:
Q: Who can certify me in NDT?
A: Although there are many ways to become
qualified for certification, you can only be
certified by the company you work for.
Q: Where do I get acceptance criteria?
A: Check your work instruction, shop traveler,
blueprint, customer specification or ask your
Level III.
Q: I cleaned my TAM panel and the
starbursts still fluoresce. What should I do?
A: Spray the starbursts with a nonaqueous wet
developer to bleed out the penetrant.As an
alternative, immerse the panel in a solvent such
as acetone and let it soak.Allow the acetone to
evaporate before replacing panel.
4
Q: I dropped my film badge in the X-ray
room and I think it got exposed. What
should I do?
A: You should report this immediately to your
supervisor or Level III so he can make the
necessary reports.
Q: Why should I recheck the calibration on
my ultrasonic test system at the end of a test?
A: Rechecking calibration at the end ensures
that the system is working as effectively at the
end of an examination as it was at the start.
E-mail, fax or phone questions to the editor
tnt@asnt.org
(614) 274-6899 (fax)
(800) 222-2768 (ext. 206)
product that has matched the engineer’s or
architect’s vision.
How important has involvement with your
ASNT section been for you and how
important do you think it would be for other
practitioners?
Being involved with ASNT really and truly
opened the door for me in the industry — opened
up the network. In order to maximize your career
potential, you have to get involved. I became
involved with ASNT almost from the beginning.
The company I was working for was slowing
down. I went to an ASNT meeting and I met Bob
Hay who works for the company I currently work
for.We were just sitting there having dinner and I
was complaining about how slow the work was
and he was complaining about how busy he was
and how he needed people. He asked me to come
down and do an interview. I did and was working
there the next Monday. If you need to look for
work you usually find it within the section in a
kind of no-stress casual atmosphere.
What advice would you offer someone
considering NDT as a career?
I think you should go in with an open mind
and don’t pigeon-hole yourself. There are lots of
different avenues to get to a career within NDT.
Also, by understanding processes, you make
yourself a lot more valuable.A lot of NDT people
do testing but they don’t do the background.
When you understand the process you are dealing
with you can apply your codes and specifications
more accurately. Continuing education is a large
factor in that.Also, read Materials Evaluation or
some of the other trade magazines to see where
trends are going. ■
Are You an
Independent Contractor?
ASNT is building a database of
contract technicians for publication
in The NDT Technician.When
completed, the database will also
reside on the ASNT Web page. It’s
free advertising. If you’d like to be
included, send us your contact info
and methods you’re trained in.
Contact the editor at (800) 222-2768
(ext. 206) or send an e-mail to:
tnt@asnt.org