| 摘要 |
PURPOSE:To perform the decision of contamination by radiations in which the processing capacity per unit time is higher as the ratio of noncontamination of a measuring target is higher, by bisecting the minimum measurement time, setting the contamination decision levels for the respective times and making decision. CONSTITUTION:A contamination decision level A1 is set lower by the difference of a standard deviation in the measurement of the measurement time t1 and the measurement time t1+t2. If the measured value at the time t1 is lower than the level A1, a measuring target is decided to be noncontaminated. When they are equal, the measurement is continued and the measurement value of the time t1+t2 and a contamination decision level A2 are compared and decided. On the other hand, when the measured value before the lapse of the time t1 exceeds the level A1, it is judged to be the contamination exceeding a contamination alarm level at that point of the time, and when such condition is reached in background measurement, it is immediately decided as equipment contamination and necessary decontamination is carried out. |
