A-A-53327A
Lightproof test. A high speed radiographic film of the applicable size shall be placed in the cassette, and all sides and edges of the cassette shall be exposed to a 100 watt incandescent lamp, operated at its rated voltage, at a distance of not more than one foot for not less than one minute. The developed test film shall be compared with a developed, unexposed film of the same lot. A density on the test film greater than that on unexposed film shall be cause for rejection. When viewed against the illuminator, the test film shall show no density variations, except that fog within 1/8 inch of film border or within 1/4 inch square at the film corners shall not be considered a defect.
Cassette liners test. A radiographic film in the sample cassette shall be exposed with an exposure time o produce a diffuse transmission density of 1.0 plus or minus 0.2. Shadows and artifacts on the test film shall be cause for rejection of the cassette.
Film contact test. Contact shall be determined by using a flat sheet of non-magnetic, bare metal, .039 plus or minus .004 inch thick, continuously perforated with holes of .098 plus 0, minus .002 inch diameter, at intervals of .16 plus 0, minus .02 inch. A flat screen of 1/4 inch mesh, made up of not more than 0.032 inch diameter, non-magnetic, bare, unsoldered wire may be used as an alternate. To facilitate the measurement of density of the film exposed during the test, the test object may have a clear area, 1/2 to 1 inch diameter, near its center. The test object shall be placed on the cassette using a cone which covers the film area but equally cuts the four film corners. Exposure shall be made to produce a diffuse transmission density of 2 to 3. Uniformity of film contact shall be indicated by a uniformly sharp exposure through the mesh. The test shall be repeated after exposure of the cassette to a minimum temperature of 120°F and a relative humidity of 80 plus or minus 2 percent for 48 hours. The intensifying screens may be removed during the conditioning period.
Grid test. The grid ratio and lines per inch shall be determined by measurement from radiographs. Radiographs of the grid shall be made as specified in the General paragraph at focal spot to film distances of 28 and 72 inches. The radiograph shall show that the space between lead strips is uniform in opacity and free from foreign matter. Non-uniform opacity or visible foreign matter shall constitute a failure.
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business