Technique and Development of Device for In-Situ Calibration of Portable Tritium Measurement Instruments

An in-situ calibration device of portable tritium measurement instruments based on PVT method was developed. The concentration of the initial tritium, which was the gas source of the device and was diluted to be the reference tritium gas according to the PVT method, was measured by the calibrated ionization chamber device and its uncertainty is 5.00%, which meet the requirements of EJ/T 1077-1998. The relative error of the concentration of the reference tritium gas between the measured result, which was carried out by the radioactive gas activity standard device and the calculated result is 0.81%. A test of calibration function of a portable tritium measurement instrument was carried out with the reference tritium gas. The results show that the calibration device can meet the needs of in-situ calibration of portable tritium measurement instruments.