T.O. 33B-1-1
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some gritty substances that can introduce scratches on the emulsion surfaces. In attempting to interpret high-density
film areas with high-intensity illuminators, care should be used to prevent overheating of the radiograph. White cotton
gloves can be ordered through the supply system.
6.7.20.2
Storage of Radiographs.
The final radiographs should be placed in film filing envelopes for final storage. These envelopes are constructed of
heavy paper to protect the films. The envelope should be identified as to the radiographs it may contain and filed in a
systematic manner to facilitate retrieval if and when necessary. Envelopes should be marked prior to insertion of the
film to prevent pressure marks. Films should not be stored in high humidity areas. Film filing cabinets are available
for film storage. Ordinary filing cabinets are not sufficiently strong to withstand the heavy loads of filed film. X-ray
films present no greater fire hazard in storage than an equal quantity of paper records. There is no necessity for
expensive vaults, equipped with elaborate fire protection devices. The storage area must be kept clean.
6.7.20.2.1
The length of time that inspection radiographs are maintained SHALL be according to AFI 37-138/9 and specific
inspection instructions. Specific inspection instructions and TO 00-20-1 SHALL be consulted to determine which
inspection radiographs SHALL become part of official aircraft/support equipment records. All radiographs SHALL be
disposed of according to AFMAN 23-110.
SECTION VIII
RADIOGRAPHIC INTERPETATION
6.8
RADIOGRAPHIC INTERPRETATION.
6.8.1
General.
The recording of an X-ray image pattern on a film is called radiography. This film, when processed, is called a
radiograph. Its interpretation is called radiographic inspection. To obtain the greatest value from this procedure,
characteristics of the radiograph must be understood and properly applied. It is possible to make erroneous deductions
based on radiography that could result in improper disposition of the material. It is the duty of the radiographer to
continually guard against this possibility. The interpretation and correlation of this information is affected by a number
of characteristics in the process that ultimately are reflected in the radiograph. The characteristics of the radiograph
are reviewed and discussed in the following paragraphs.
6.8.2
Radiographic Image Quality.
Radiographic interpretation cannot be performed without knowledge of the image quality. Knowledge of the image
quality tells the film reader the minimum size of discontinuities he can expect to visualize.
6.8.3
Sensitivity.
Radiographic sensitivity is defined as the differential in thickness in terms of percentage of total thickness that can be
recorded by radiography. This sensitivity is a result of X-ray image contrast, film contrast, image sharpness, image
distortion and image density obtained in the radiograph. In a normal radiographic practice no attempt is made to
record the ultimate radiographic sensitivity in each radiograph. However, it is required that a certain quality of
radiography be attained to assure satisfactory inspection. To assure this quality of inspection by radiography,
penetrameters (image quality indicators) are used. The application of penetrameters is discussed in an earlier section.
6.8.3.1
Examination of the penetrameter image on the radiograph will indicate the sensitivity. Correct radiographic procedure
will show the image details of the penetrameter sharply defined. However, the penetrameter sensitivity is a gauge of a
certain standard of sensitivity. It cannot actually measure the sensitivity in percent. This idea of penetrameter
sensitivity has several limitations that should be kept in mind:
