| 摘要 |
<p>PURPOSE:To take a previous measure to a radiation exposure accident by integrating dosage and updating integral dosage, and warning its limit value. CONSTITUTION:A radiation measurement part 6 detects radiation 3 and outputs a measurement signal 4a corresponding to the its dosage rate and an arithmetic and storage part 10 inputs the signal 4a to find the time integral value of the dosage rate, adds the value to old integral dosage Bo stored in a nonvolatile memory 71 to obtain new integral dosage Bn and update the old integral dosage, and outputs a signal 8a indicating the dosage Bn at a specific time period. Here, radiation exposure dosage Ti of semiconductor devices 4b, 10a, and 11a provided to a measurement part 6, the arithmetic and storage part 10, and a warning part 11 nearly correspond to the dosage values Bo and Bn and a radiation exposure dosage maximum value Tio with which neither performance deterioration nor functional breakage is caused is almost determined for each semiconductor device. When the dosage Bn reaches the limit value at which there is no possibility of a radiation exposure accident, the warning part 11 outputs a warning signal, so that the approach of the period where the exposure accident is generate can be known.</p> |
