The response of health physics instruments to temperature variations

The response of radiation measuring instruments will vary due to the temperature sensitivity of circuit components and detectors. Tests on approximately 60 dose rate instruments showed significant changes in response to temperature variation (/minus/20 to +50/degree/C). Comparing instrument response at a constant 20/degree/C with responses over the experimental range of temperatures revealed that dose rate responses of some instruments changed over 100%. In tests on a series of instruments of the same model, the change in response varied from instrument to instrument, making it impractical to predict instrument response without tests on the specific instrument. Scintillation detectors, ion chambers, and proportional counters are more sensitive to temperature than are Geiger-Mueller detectors, but stabilization circuits can adequately compensate for the sensitivity of scintillation detectors. Response curves are presented for several instruments over the temperature range of /minus/20 to +50/degree/C. 2 refs., 5 figs., 2 tabs.