Method for accurately controlling photographic density during radiographic inspection

Abstract

The invention discloses a method for accurately controlling photographic density during radiographic inspection. The method includes 1), placing films and a radial dosimeter under each step of step test blocks, and clearing accumulated data of the radial dosimeter to zero; 2), exposing; 3), washing and airing the exposed films to obtain negative films, measuring optical density of the negative films through the radial dosimeter and reading corresponding accumulated doses; 4), reading accumulated doses AH and AL respectively corresponding to an upper-limit black matrix and a lower-limit black matrix required by technological detecting regulations from the negative films, and setting an alarm threshold value of the radial dosimeter into a dose value corresponding to a suitable optical density or other values in range of [AL,AH] as required; and 5), transilluminating and exposing to-be-detected workpieces, stopping exposing immediately when the radial dosimeter sends alarms, and keeping the optical density of the negative films in a value range required by the regulations. The accumulated doses of the radial dosimeter are adopted to control exposure time so as to control the optical density of the films, so that exposure curves are not needed to produce too much, time and energy are saved, and problems of fixing transilluminating focal distance, fixing tube voltage and the like are not needed to be considered.

Description

[0001] technical field [0002] The invention relates to a method for precisely controlling the blackness during radiation detection. Background technique [0003] In the current industrial ray inspection, to obtain the appropriate blackness value is achieved by controlling the exposure. The exposure is determined by checking the exposure curve. According to the exposure curve, the exposure when the workpiece is transilluminated is determined, so that the film can be tested. The blackness value required by the regulations. However, it is cumbersome to make the exposure curve, and the exposure curve needs to be redone if the transillumination conditions are changed. If there is no corresponding exposure curve, the exposure amount cannot be determined, so that a suitable blackness value cannot be obtained, which brings inconvenience to the radiation detection. Contents of the invention [0004] The technical problem to be solved by the present invention is to provide a meth...

AI Technical Summary

Problems solved by technology

However, it is cumbersome to make the exposure curve, and the exposure curve needs to be redone if the transillumination conditions are changed. If there is no corresponding exposure curve, the exposure amount cannot be determined, and thus the appropriate blackness value cannot be obtained, which brings inconvenience to the radiation detection.

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