Determination of Detection Efficiency Curve for a Gas Monitor with a Built-in Germanium Detector

Calibration techniques for a gas monitor with a built-in germanium detector were studied. The peak-detection efficiencies were precisely determined with some calibration gases. In order to obtain more reliable efficiency curves from the limited data of calibration gases, an interpolation technique using a multi-γ point source was applied. And also, the feasibility of simple calibration with the point source located at an appropriate single position was discussed. As a result, the efficiencies obtained with the calibration gases show good agreement with the efficiency curves derived by the interpolation technique. The efficiencies also agreed with efficiency curves determined by the simple calibration within an error of 4%.