| 摘要 |
PURPOSE: To provide a method for monitoring the detection sensitivity of a device for reading the radiation picture of an object recorded on a light stimulative fluorescent screen by exposing the light stimulative fluorescent screen by irradiation light. CONSTITUTION: This method consists of a process for scanning the light stimulative fluorescent screen by stimulation irradiation light, the process for detecting emitted light quantity by stimulation scanning, the process for converting the detected light quantity to electric signals, the process for compressing the electric signals by a square root amplification processing and the process for digitizing the compressed electric signals. A noise dispersion value σe <2> corresponding to a sensitivity class set at the point of time of preparing the radiation picture is called from a prescribed table. Then, the ratio of σy <2> /σe <2> is calculated and a threshold value operation is performed. As a result, in the case that a radio value σy <2> /σe <2> exceeds a threshold value T+ or in the case that it is smaller than the threshold value T- , alarm signals are prepared. |
