Title: AUDITOR%20NDT%20TRAINING
1AUDITOR NDT TRAINING
- The purpose of this training is to give the
auditor a familiarity of the quality control and
quality assurance systems associated with
Nondestructive testing.
2Introduction
- The reference material used in this presentation
is SNT-TC-1A, ASTM Standards 2000 edition,
Nondestructive inspection evaluation checklist
(from FAA sight). - From this presentation you should be able to be
able to understand and evaluate an NDT facilities
quality systems.
3Agenda
- Training and Certification.
- Audit/Evaluation Surveillance.
- Liquid Penetrant Inspection.
- Magnetic Particle Inspection.
- Radiography Inspection.
- Ultrasonic Inspection.
- Eddy Current Inspection.
4Overview
- It is recognized that the effectiveness of
nondestructive testing applications depends upon
the capabilities of the personnel who are
responsible for and perform it. - As the auditor you will be required to evaluate
NDT personnel and facilities to make a
determination of compliance in accordance with
the vendors manual, and required specifications. - The five elements that can be used to evaluate
any NDT organization from manufacturing to
maintenance. -
-
5Overview
- 1) Documentation- written procedures,
processes specifications and/or methods used by
the vendor in performance and controls of NDT
activities. - 2) Organization- relationship of NDT
organization to management. - 3) Environment- the general physical
condition of the facility, e.g.,housekeeping,
storage, safety, consumable management,
equipment. - 4) Calibration- process by which an item is
checked to a standard. - 5) Training- methods used and records
maintained to train and retrain NDT personnel
6Training and Certification
- The requirements for training, qualification, and
certification in each NDT method should be part
of the vendors manual or written practice. - Some recommended practices are ASN-TC-1A,
ANSI/ASNTCP89 NAS 410 (previously Mil Std 410E),
ATA105, ISO 9712.
7Training and certification
- Three basic Levels of qualification.
- 1) Level I- An NDT Level I individual should
be qualified to properly perform specific
calibrations, specific NDT, and specific
evaluations for acceptance or rejection
determinations according to written instructions
and to record results.The NDT Level I should
receive the necessary instruction or supervision
from a certified Level II or III individual.
8Training and certification
- 2) Level II- An NDT Level II individual should
be qualified to set up and calibrate equipment
and to interpret and evaluate results with
respect to applicable codes, standards and
specifications.The Level II should be thoroughly
familiar with the scope and limitations for
methods for which qualified and should exercise
assigned responsibilities for OJT training and
guidance of trainees and Level I personnel.
9Training and certification
- 3) Level III- An NDT Level III individual
should be capable of developing, qualifying, and
approving procedures, establishing and approving
techniques, interpreting codes, standards, and
specifications and procedures and designating
the particular NDT methods, techniques, and
procedures used. The NDT Level III should be
responsible for the NDT operations for which
qualified and assigned and should be capable of
interpreting and evaluating results in terms of
existing codes, standards and specifications.
10Training and certification
- Level III continued- The NDT Level III should
have sufficient practical background in
applicable materials, fabrication and product
technology to establish techniques and to assist
in establishing acceptance criteria when none are
otherwise available. The NDT Level III should
have general familiarity with other appropriate
NDT methods, as demonstrated by an ASNT Level III
examination or other means. The NDT Level III ,
in the methods in which certified, should be
capable of training and examining NDT Level I and
II personnel for certification in those methods
11Training and certification
- Some procedure also may call out for a trainee, a
trainee is not authorized to accomplish,
interpret or report any inspection requirements. - Some procedures may also call out for an NDT
instructor an instructor is usually a Level II
working under direction of the companies Level
III. - These Levels may also be subdivided into approval
to comply with specific procedures such as
conductivity, ultrasonic thickness measurement(
should be in the vendors written practice)
12Training and certification
- The required amount of training required to
qualify and certify the NDT inspector should be
part of the vendors written practice. - The requirements of each recommended practice
vary on the amount of formal training and
experience. - Personnel should complete sufficient organized
training to become thoroughly familiar with
principles and practices of the specified NDT
method.
13Examination
- May be accomplished by an outside agency, but
does not alleviate the employer of
responsibility. - For Level I and II a general, specific, and
practical test is required.(ASNT) - For Level III a basic, method, and specific test
is required.(ASNT)
14Examination
- The Level III shall be responsible for the
administration and grading of examinations for
Level I Level II or other Level III personnel. - For Level I or II personnel the composite grade
should be determined by averaging the results of
the general, specific and practical exam.(ASNT) - Note-ISO 9712 has a general and specific exam and
each exam will have a written and a practical
part - For Level III personnel the composite grade
should be determined by averaging the results of
the basic (required only once), method, and
specific exams.(ASNT)
15Examination
- Minimum passing grade should consist of no
individual test grade below 70 and the composite
grade should be no less than 80 (ASNT). - When an examination is administered and graded
for an employer by an outside agency and the
outside agency issues a pass or fail only, on a
certified report the employer may accept the pass
grade as a 80 for that particular examination
(ASNT).
16Examination
- Also an eye exam should be accomplished
annually for near vision acuity and every 3 years
for color contrast Differentiation. - Re-certification for Level I and II should be
every 3years, Level III every 5 years.(ASNT)
17Training and certification
- The employers certification shall be deemed
revoked when employment is terminated. - A Level I, II or III certification may be
re-instated to the former NDT Level by a new
employer based on examination, provided all the
all these conditions have been met. - 1) employee has proof of prior certification.
- 2) The employee was working in the capacity
to which certified within 6 months of
termination. - 3)The employee is being re-certified within
within 6 months of termination. -
18Training and certification
- 4) Prior to being examined for certification,
employees not meeting the above requirements
should receive additional training as deemed
appropriate by the Level III.(ASNT)
19Training and certification
- A Level I, II, or III whose certification has
been terminated may be re-instated to the former
NDT Level, without a new examination, provided
all the following conditions have been met. - 1) The employer has maintained the
personnel certification records. - 2) The employees certification did not
expire during termination. - 3) The employee is being re-instated within
6 months of termination (ASNT)
20Audit / Evaluation and Surveillance
- Documentation
- 1) Does the facility have a manual to
include an organizational chart? - 2) Does the manual contain or refer to the
appropriate specifications, are they current ,
and available? - 3) Are there provisions in the manual for
internal review/evaluation and are the
appropriate records maintained?
21Audit / Evaluation and Surveillance
- 5) Are there procedures in place to revise the
manual? - 6) Are there procedures in place for retention of
records? - 7) Does the manual contain procedures that
address nonconformities? - 8) Are the manuals and procedures available to
and used by qualified personnel? - 9) Does the manual contain controls for
subcontracts for NDI services? - 10) Does the manual contain controls for
management of NDI products, materials, and
consumables?
22Audit/Evaluation and Surveillance
- 11) Is there a separate NDI organization in the
facility? - 12) Does the NDI manager or equivalent have
direct line authority to the NDI qualified
personnel? - 13) Are the NDI requirements provided to the NDI
inspection personnel by use of written practice? - 14) Does the NDI manager, or equivalent, review
the quality assurance system to monitor
compliance to the FAA approved data? - 15) Are proper shift change procedures in place?
23Audit/Evaluation and Surveillance
- Environment
- 1) Is the size of the work area sufficient to
perform the NDI inspections? - 2) Is there adequate work area for storage and
separation of NDI materials? - 3) Is there a method for controlling and
segregating nonconforming NDI equipment and
materials? - 4) Are appropriate manuals, procedures, and other
documentation available for use by qualified
personnel?
24Audit/Evaluation and Surveillance
- Environment (continued)
- 5) Are adequate parts handling systems (cranes,
hoists, lifts etc) available? - 6) Do routing documents specify the operation
needed and in what sequence? - 7) Is adequate protection provided to parts
during handling and routing? - 8) Is metal to metal contact of finished surfaces
prevented during handling? - 9) Are obsolete documents removed from inspection
areas
25Audit / Evaluation and Surveillance
- Calibration
- 1) Is there a procedure for calibrating
inspection devices to certified standards? - 2) Are there procedures for segregation of
functional and nonfunctional equipment? - 3) Are procedures in place to ensure
repaired equipment is recalibrated? - 4) Are reference standards properly
labeled, stored and used? - 5) Are independent data available for
reference standards, ie., drawings, metrology,
etc.?
26Audit / Evaluation and Surveillance
- Calibration (continued)
- 6) Are the calibration methods documented?
- 7) Do calibration methods include environment
controls, standards to be used, and accuracy
requirements? - 8) Are setup verifications performed on all
shifts as appropriate?
27Liquid Penetrant (ASTM E1417)
- 2 Basic Types
1) Type I
Fluorescent 2) Type II
Visible - 4 Methods 1) Method A Water washable 2)
Method B Post-emulsified, lipophilic 3) Method
C Solvent-removable 4) Method D
Post-emulsified, hydrophilic
28Liquid Penetrant
- Sensitivity Levels These levels are for Type I
penetrants only. Type II penetrants have only a
single sensitivity and is not represented by any
level. 1) Sensitivity Level ½ - Very low 2)
Sensitivity Level 1 Low 3) Sensitivity Level
2 Medium 4) Sensitivity Level 3 High 5)
Sensitivity Level 4 Ultrahigh
29Liquid Penetrant
- Developers shall be the following forms 1) Form
a Dry powder 2) Form b Water-soluble 3)
Form c Water-suspendable 4) Form d
Nonaqueous for Type I fluorescent. 5) Form
e Nonaqueous for Type II visible dye. 6)
Form f Specific application
30Liquid Penetrant
- Solvent removers shall be of the following
classes 1) Class 1- Halogenated 2)
Class 2 Nonhalogenated 3) Class 3 Specific
application
31Liquid Penetrant
- Quality control and system performance. 1)
Penetrant contamination Accomplished daily to
determine if any of the following conditions are
evident precipitates, waxy deposits, white
coloration, separation of constituents, surface
scum, or any other evidence of contamination or
breakdown.
32Liquid Penetrant
- Developer contamination ( Aqueous soluble and
suspendable) accomplished daily. 1)
Checked for fluorescence, as appropriate, and
coverage by immersing an aluminum panel. Failure
to uniformly wet the panel or any observed
fluorescence is unsatisfactory and the developer
shall be replaced.
33Liquid Penetrant
- Developer concentration Aqueous soluble and
suspendable accomplished weekly.
1) Checked with a hydrometer to supplier
specification. - Developer condition (Dry) accomplished daily.
1) Check to
see that the developer is fluffy and not caked
also check for fluorescent specks 10 or more
specks or any caking is unsatisfactory
34Liquid Penetrant
- Water wash pressure checked each shift. 1)
Should not exceed 40 psi, minimum distance 12
inches from part. (need not be recorded) - Water Temp. Checked each shift 50 to 100
degrees F. Note If immersion rinse is
being used the water should be agitated.
35Liquid Penetrant
- Black Light intensity Checked daily. 1)
Minimum 1000 micro watt/cm2 at 15 inches also
check filter for damage. - Inspection area cleanliness Checked daily (Need
not be recorded) - Water based penetrant water concentration
Checked weekly. 1) Checked with a
refractometer to MFG. Specifications. -
36Liquid Penetrant
- Non-water based penetrant water content (Method
A) Checked monthly. 1)Test method D95 or Karl
Fischer method. 5 water content Max. - Emulsifier concentration (hydrophilic) Checked
weekly. 1) Checked with a refractometer to
MFG specifications.
37Liquid Penetrant
- Penetrant sensitivity Checked weekly. 1) A
comparison with unused sample if the sensitivity
drops below unused material is unsatisfactory. - Fluorescent brightness Checked
quarterly. 1) Usually accomplished in a
Lab. With a fluorometer or a photofluorometer
must maintain 90 of original brightness.
38Liquid Penetrant
- Penetrant removability (Method A) Checked
monthly. 1) Test shall by accomplished using
normal wash parameters compare with unused
material. - Emulsifier removability Checked
monthly. 1) Compare with unused material
on test piece or production part.
39Liquid Penetrant
- Emulsifier water content (lipophilic) Checked
monthly. 1) Test method D95 or Karl Fischer
method usually sent to a Lab. - Drying oven calibration Checked quarterly (may
be reduced or extended when substantiated by
performance)
40Liquid Penetrant
- Light meter calibration Checked semiannually
(may be reduced or extended when
substantiated) 1) Both black light and
visible light meters IAW MIL-STD-45662 or
ANSI/NCSL Z540-1
41Liquid Penetrant
- Preparing and Precleaning All coatings and
other conditions such as paint, plating,
corrosion, scale, smeared metal, welding flux,
chemical residues or any other material that
could prevent from entering discontinuities,
suppress dye performance, or produce unacceptable
background.
42Magnetic Particle(ASTM E1444)
- Magnetic particle inspections can be accomplished
wet, dry, fluorescent, visible, utilizing AC or
DC current induced magnetism in the circular,
longitudinal direction, or multidirectional. - FAR part 145.49 you must have equipment for wet
and dry magnetic techniques, residual and
continuous methods and portable for inspections
of welds both on or off the aircraft.
43Magnetic Particle
- Quality control and performance checks.
- Light intensity. Check daily 1) Black Light
minimum intensity 1000 micro watt/cm2 also check
filter for damage. 2) Visible Light
minimum 100fc or 1000 lx. 3) Ambient Light
2fc maximum.
44Magnetic Particle
- System performance using a test piece or ring
specimen. Check daily. - Wet particle concentration. Check each shift
Shall be .1 to .4ml in a 100ml sample fluorescent
particles. Shall be 1.2ml to 2.4ml for
nonfluorescent particles. - Gauss meter (Teslameter) reading zero. Check each
use. - Gauss meter (Teslameter) accuracy. 6 months.
- Ammeter accuracy. Check 6 months usually
accomplished with a shunt and a calibrated
ammeter IAW MFG specifications -10.
45Magnetic Particle
- Quick break check. Check 6 months - can use an
oscilloscope or other method recommended by the
MFG. - Dead weight check. Check 6 months Yokes and
permanent magnets (when allowed) 1) A.C.
shall have a lifting force of at least 10lbs with
a 2 to 4 inch spacing. 2) D.C. lifting force
30lbs 2 to 4inch spacing, or 50lbs 4 to 6inch
spacing.
46Magnetic Particle
- Wet particle contamination. Check each shift/
weekly. 1) Examine the the liquid above the
precipitate with a black light. fluorescence
should be comparable to original solution. 2)
Examine the graduated portion of the tube both
visible light and black light for striations or
bands, different in color or appearance this may
indicate contamination 30 maximum.
47Magnetic Particle
- Water break test. Check daily Only on water
based vehicle with a wetting agent. 1) Flood the
part with conditioned water, and the appearance
is noted after flooding is stopped. If film of
suspension breaks, exposing bare surface,
insufficient wetting agent is present or the part
has not been cleaned properly.
48Magnetic Particle
- Preparation of parts. 1) Demagnetize the
part before examination if prior operations have
produced a residual magnetic field. 2)The
surface of the part to be inspected shall be
smooth, clean, dry, and free of oil, scale,
machining marks, or other contaminants or
condition that might interfere with the
efficiency of the inspection.
49Magnetic Particle
- 3) No coating that may prevent detection of
surface defects. Paint or chrome greater than
.003 inch in thickness, and ferromagnetic coating
such as electroplated nickel greater than .001
inch
50Radiography
- Safety and exposure requirements are regulated by
the NRC and State agencies. - Individual exposure should be maintained on
record at the facility. - Industrial radiation license is issued by the
state and also thru the NRC for the use of a
radioactive isotopes. - CFR 10 Parts 19, 20, 21, 30, 34 and 70 apply to
regulating and licensing for use of radioactive
isotopes.
51Radiography
- CFR 10 Part 19 regulations establish the
requirements for posting of notices, work
instructions and reports by licensees to persons
(employees) who participate in licensed
activities and options available to employees in
connection with NRC inspections of licensees.
Part 19 establishes the right and
responsibilities of individuals and the NRC on
any matter within the commissions jurisdiction.
52Radiography
- CFR 10 Part 20 establishes standards for
protection against radiation hazards arising out
of activity under licenses issued by the NRC.
Part 20 discusses the concept of ALARA, and
standards for dose limits for all persons who
receive, possess, use or transfer material
licensed under the NRC.
53Radiography
- CFR 10 Part 21 establishes reporting procedures
and requirements for any individual or
responsible officer of a firm constructing,
owning, operating or supplying components
licensed or regulated by the NRC that fail to
comply with or regulations relating to safety.
Part 21 establishes time limits for reporting to
the NRC when basic component defect or failure
pose a substantial hazard.
54Radiography
- CFR 10 Part 30 prescribes rules applicable to all
persons in the United States governing domestic
licensing of byproduct material under the Atomic
Energy Act of 1954, as amended, and Title II of
the Energy Reorganization Act of 1974.
55Radiography
- CFR 10 Part 34 establishes requirements for the
issuance of licenses for the use of sealed
sources containing byproduct material and
radiation requirements for persons using such
sealed sources in radiography. Nothing in this
part shall apply to uses of byproduct material
for medical diagnosis or therapy.
56Radiography
- Part 34 cont. Includes requirements for operating
and emergency procedures, for training of
radiography personnel, equipment performance,
record maintenance, securing and storing
radiographic exposure devices and personal
audits. - CFR 10 Part 70 requirements for packaging,
preparation for shipment, and transportation of
licensed material.
57Radiography
- Radiation detection devices. 1) Survey Meter
Measures dose rate. Gas filled tubes are used in
the 2 types of survey meters the ionization
chamber survey meter and the Geiger-Muller
(or G-M) survey meter. The Ion chamber
survey meter is primarily used. Survey meters
should be calibrated every 6 months (CFR 10 Part
34)
58Radiography
- 2) Pocket Dosimeter The pocket dosimeter is
basically an air- filled ion chamber.The pocket
dosimeter uses a charger to apply an electric
charge to zero the quartz fiber as the dosimeter
is exposed to ionization radiation, the ions
created will neutralize the charge on the fiber
and wire causing the fiber to move toward the
wire giving a reading of exposure in
milliroentgen (mR). The pocket dosimeter should
be calibrated every12 months.
59Radiography
- 3) Film Badge or TLD Must be sent out monthly
to a certified Lab for reading, they will send
back a report of individual exposure, which must
become a part of the individual personal exposure
record. - 4) Rate Alarm Set to 500 mrem/hr. calibrate
every 12 months, may only be required for use
with isotopes.
60Radiography
- ALARA Is an acronym for as low as reasonably
achievable which means make every effort to
maintain radiation exposures as far below the
dose limits as is practical. - The radiation area shall maintained to a maximum
of 2 millirems.
61Radiography
- Storage of materials 1) Film should be
stored in a cool dry place on its end, the
expiration date should be on the box. 2)
Chemicals (starter, fixer, and developer) should
be stored in an appropriate locker. Most of these
chemicals have a 2 year life limit marked on the
box.
62Radiography
- Radiation Safety Officer. 1) The RSO is the
individual with the responsibility for overall
radiation safety program and who meets the
requirements. 2) The RSO shall ensure that
radiation safety activities are being performed
in accordance with approved procedures and
regulatory requirements in the daily operation of
the licensees program. 3) The RSO shall
establish and oversee all operating, emergency,
and ALARA procedure.
63Radiography
- RSO cont. 4) Overseeing and approving all
phases of the training program for radiographic
personnel. 5) Ensure that the required radiation
surveys and leak tests are performed and
documented in accordance with regulations. 6)
Ensure that personal monitoring devices are
calibrated and used properly. 7)Ensuring that
operations are conducted safely and to assume
control for instituting corrective
actions.
64Radiography
- Radiographer should have had not only the
required amount of radiography training, but
should have also had training in radiation
safety. If the individual is using radioactive
isotopes must meet the requirements of CFR10 Part
34. - Radiographer Assistant Should have training in
radiation safety and if using an isotope must
meet the requirements of CFR 10 Part 34.
65Ultrasound
- Ultrasonic testing is the process of applying
ultrasonic sound (above 20,000Hz) to a specimen
and determining its soundness, thickness or some
physical property. - Ultrasonic pulse echo instrument generates high
voltage electrical pulse of short duration. These
pulses are applied to the transducer which
converts them into mechanical vibrations that are
applied to the material.
66Ultrasound
- Ultrasonic through transmission Requires 2
transducers one for sending and the other for
receiving. Short or continuous waves are
transmitted into the material.The quality of the
material being tested is measured in terms of
energy lost by the sound beam as it travels
through the material.
67Ultrasound
- Contact testing Where the transducer is coupled
to the material through a thin layer of couplant. - Immersion testing Both the material and the
transducer are immersed in a tank of couplant
(usually water). - Couplant The primary purpose of a couplant is
to provide a suitable path between the transducer
and the test surface - NOTE Do not use glycerin as a couplant on
aluminum may cause corrosion
68Ultrasound
- Longitudinal wave Have particle vibrations in a
back and forth motion in the direction of
propagation. - Shear waves Have particle vibrations
perpendicular to the direction of wave motion.
Shear waves will not travel through liquid or
gas. - Surface waves Are elastic vibrations whose
energy is confined to a narrow region just below
the surface.
69Ultrasound
- Displaying ultrasonic indications Three basic
types A-scan, B-scan, C-scan. A-scan is a time
versus amplitude display which reveals a
discontinuity using a pip on a CRT. The A scan is
read from left to right. B-scan typically
uses an oscilloscope type screen to display a
cross sectional view of the material being tested.
70Ultrasound
- C-scan Is a Plan View presentation similar
to an X-ray picture.The C-scan shows shape and
location of the discontinuity but does not show
depth.
71Ultrasound
- Calibration standards Such as the IIW block,
Miniature calibration block, Area amplitude
blocks, DSC blocks and Distance amplitude
blocks.Calibration standards are used for
adjustments for simple ultrasonic testing
procedures and to check on the reproducibility of
measurement.
72Ultrasound
- Reference standards Aid in calibrating the
instrument and indicating whether the
discontinuities expected will be detected by
preselected sensitivity. The standards apart from
facilitating initial adjustment of the
instrument, also check on reproducibility of the
measurement. - Reference standard material should be identical
to the object being tested in chemical
composition, heat treat, physical and mechanical
characteristics.
73Ultrasound
- Facility being evaluated should have the
appropriate standards, transducers, equipment,
technical data. - To prepare a part for ultrasonic inspection the
part should be free of loose paint, dirt, and
scale.
74Eddy Current
- Eddy current testing is a non-destructive test
technique based on inducing electrical currents
in the material being inspected and observing the
interaction between those currents and the
material. - Eddy Current can be used for crack detection,
conductivity measurement, nonconductive coating
thickness, material loss due to corrosion - Indicating devices An important part of the
eddy current test system is the part of the
instrument that gives the technician of the
change in impedance. As usual there are several
different types of devices used. -
75Eddy Current
- 1) Analog meter 2) Digital
meter 3) Oscilloscope 4) Impedance
plane 5) Strip chart recorders -
76Eddy Current
- Eddy Current Coils and Probes Inspection coils
can have a variety of forms and can be arranged
in a variety of ways. The choices of the type of
arrangement of the inspection coil depends on the
test situation. 1) Single coil
absolute 2) double coil absolute 3)
Differential coil arrangement 4)
Reflection coil arrangement
77Eddy Current
- The previous coil arrangements can be installed
on a variety of probe configurations such as. 1)
Surface probes 2) Holes probes 3)
Encircling 4) Internal (bobbin) - Erroneous indications can come from nonspecific
variations in the test object such as coating
thickness changes, conductivity changes, even
electrical interference.
78Eddy Current
- Reference standards should be of the same
material chemical composition, heat treat,
physical and mechanical properties as the part to
be inspected.
79Eddy Current
- Conductivity measurements Conductivity
measuring can be used to determine a materials
temper if you know the alloy, it can be used to
sort different alloys, it can also be used to
determine heat damage on aluminum alloys.
Conductivity measurement alone can not be used to
identify different alloys due to the overlap of
conductivity ranges.
80Eddy Current
- Conductivity cont. Accomplishing a conductivity
measurement is achieved by using a conductivity
instrument setting it up with known calibration
standards of known value. A reading is given in
IACS (International Annealed Copper Standard)
These standards should be checked periodically
for accuracy due some materials conductivity
changes with age
81Eddy Current
- Conductivity cont. Another way is to make a
conductivity curve with an impedance plane
instrument utilizing the calibration standard. - Surface and subsurface defects can be discovered
using eddy current by using different probe and
coil configurations. As a rule the lower the
frequency used the larger the depth of
penetration.
82Eddy Current
- As with any other NDT method the facility must
have the appropriate equipment, probes,
standards, technical data and trained personnel
to perform the work.
83Summary
- In this class we have covered training and
certification, audit and evaluation and 5 of the
most commonly used NDT methods in general terms.
- Read the vendors written practice, and look at
the specifications in which inspections are to be
accomplished Ensure that they have the required
materials to accomplish the work. While using the
1A standard and a little familiarity with NDT a
thorough audit will be accomplished.
84Information
- Additional information on the subject of NDT can
be purchased from the ASNT at asnt.org