RADIOGRAPHIC
INTERPRETATION
Art of extracting maximum information
from radiography image.
This requires subjective judgment of the
interpreter.
STEPS IN THE R.T TEST.
STEP 1:
STEP 2:
Produce the radiograph.
Determine The Quality Of The
Radiographic image.
STEP 3: Interpret All Indications.
STEP 4: Evaluate the test and test
results.
STEP 5: Record and communicate test
results.
STEPS IN THE R.T TEST.CONT….
Interpret: to give the meaning
of to explain.
Evaluate : to determine the
worth of something.
STEPS IN THE R.T TEST.CONT….
• Indication: a density change appearing on a radiograph.
• False indications: film artifacts, screen Problems, fog, scatter x-ray
diffraction.
• Discontinuity: a break in the test specimen’s structural continuity.
• Defect: a condition that renders the specimen unsuitable for intended
service.
FACTORS AFFECTING THE INTERPRETATION OF TEST
RESULTS:
• Type of materials being welded.
• Type of weld and joint preparation.
• Welding processes.
• Radiographic process.
• Radiographic technique.
• The applicable code or standard.
FUNCTION OF A QUALIFIED INTERPRETER.
1.Define radiographic quality.
Analysis of R.T technique and development regarding procedures.
2: analysis the radiographic image to determination of the nature and
extent of any abnormal deviation.
FUNCTION OF A QUALIFIED INTERPRETER CONT…
3. Evaluate by comparing the
interpreted.
Information with standard / specification.
4. Report results: accurately and
clearly.
QUALITIES DESIRED FOR A GOOD INTERPRETER.
1. KNOWLEDGE.
2. EXPERIENCE.
3. VISION ACUITY.
(A). EYE VISION FREE FROM COLOUR
BLINDNESS.
(B). NEAR VISION ---J2.
TOOLS REQUIRED FOR PROPER INTERPRETATION.
(A). Working environment to produce maximum
comfort and minimum fatigue for
interpreter.
(B). Room with sub due lightening. The back
ground lightening shall be equal to the
transmitted light through the radiograph.
No glare or reflected light.
(C). Good illuminator with light intensity
suitable for the of density. Uniform
distribution of light.
300 – 100 candles / square meter.
TOOLS REQUIRED FOR PROPER INTERPRETATION.
CONT…
(D). Densitometer and density
comparison strips.
(E). Reference radiographs.
(F). Magnifying glass and glass
marking pencil.
VIEWING OF RADIOGRAPHS.
SLNO:
OBJECTIVE
1.
ILLUMINATOR
2.
BACKGROUND
LIGHTINING
FILM TYPE
3.
4.
5.
6.
SUB.OBJECTIVE
(INDIVIDUALS)
VISUAL ACUITY
TRAINING
KNOWLEDGE
CONTRAST
EXPERIENCE
IMAGE
AGE
MAGNIFICATION
DISTANCE OF VIEWING DARK
ADAPTATION
RADIOGRAPHIC INTERPRETATION
Get all facts and give a balanced judgment.
Reporting:
1. Unambiguous and concise.
2. Phrases like “no significant defects”
should be avoided.
3. Report should locate the
defect, name, size, and possible depth.
4. Sketches can accompany report indicating
location and nature of defect.
HANDILING THE RADIOGRAPH
1. Hold the radiograph with the
fingers across the edges.
2. The film has to be clipped to
the illuminator, use corners.
3. Never touch the surface.
HANDILING THE RADIOGRAPH
CONT..
4. Examine the film with reflected light for processing quality, drying
marks, stains etc.
5. Check for the graininess over
development and too high temperature causes excessive graininess.
EXPOSURE CALCULATIONS,VARIABLES.
1.
2.
3.
4.
5.
6.
7.
8.
GEOMETERY.
SOURCE TYPE AND STRENGTH.
FILMS-----TYPE.
SCREENS.
DENSITY.
STEEL EQUIPMENT.
MATERIAL THICKNESS.
CONTROL OF SCATTER.
INTERPRETER SHOULD HAVE KNOWLEDGE OF THE
FOLLOWING:
The characteristics of radiation source and energy level with respect
to material being tested.
The characteristics of recording media (film) in response to selected
source and energy level.
The processing of recording media with
respect to image quality.
The product form being radiographed.
INTERPRETER SHOULD HAVE KNOWLEDGE OF THE
FOLLOWING:
The possible and most probable types of discontinuities that can occur
.
The possible variation of discontinuity images as a function of
radiographic geometry and other factors.
R.T STANDARDS,CODES &.SPECIFICATIONS
Standards.
Specifications.
Codes.
Recommended standards.
Procedures.
These are documents which indicate the buyer the quality and other
requirements of a component/system services.
STANDARDS ARE PREPARED BY THE FOLLOWING:
I.
II.
A company
BHEL
A group of organization with like
interest.
III. NATIONAL BUREAU OF
STANDARDS.(EX): BIS, DIN, ANSI.
IV. INTERNATIONAL STANDARDS.
(EX): ASME, API, AWS, TEMA.
CLASSIFICATION OF STANDARDS PRETAINING TO
RADIOGRAPHY:
STANDARDS PRETAINING TO IMAGE QUALITY.
EXAMPLE : E747,E.1025.
DIN 54109
AFNOR
NF.A04-304
ISS 3657
BSS
3971.
STANDARDS ARE PREPARED BY THE FOLLOWING.
CONT…
Standards pertaining to method of test.
Radiographic arrangement criteria for film selection, selection of
radiation energy etc….
example:
ASTM-E94.
BSS-2600,2910.
DIN-54112.
ASME-SEC V ARTICLE:2.
JIS-23104,23105.
ISS-2595.
STANDARDS ARE PREPARED BY THE FOLLOWING.
CONT…
Standards pertaining to specific structures and products:
Specify testing methods and specific component such as Boilers,
Pressure Vessels, Pipe Lines etc.
ASME SEC I,III,VIII
B.S.S 5500.
API
6A,1104
STANDARDS ARE PREPARED BY THE FOLLOWING.
CONT…
Collection of reference Radiographs.
Classifying defects by their shape, size, and distribution etc…
example: E.446,E.186,E.280,E.390.
IIW collection of reference radiographs of welds.
Standards pertaining to RADIATION SAFETY.
PROCEDURE
A document in corporating details to be carried out for meeting the
code/ standard/ specification & requirements.
A STEP