Radiation calibrator 844-36

laboratory

To permit field re-calibration of scintillation and process GM detectors, Victoreen has designed the Model 844-36 Process Monitor Calibration Fixture. Process radiation monitor detectors consist of a scintillation crystal, that converts the incident radiation into a light pulse, a photomultiplier tube (PMT), to amplify the light into a useable electronic pulse and a preamplifier, to condition and transmit the pulses received to a pulse counting and display device. The high voltage applied to the PMT directly affects the gain of the detector. Key Features Reproducible calibration geometry 2 inches of 4 Pi lead shielding to reduce background response Reversible source drawer for Beta and Gamma scintillation detector calibration Scintillation detector dead time verification drawer available GM detector adaptors available Disassembles easily for field transportation The gain and low discriminator settings directly affect the efficiency of the detector. Because the gain of the PMT used in scintillation detectors decreases with age, it is necessary to periodically readjust the detector high voltage to ensure the gain the detector is operating at is the same as the gain the detector was operating at when the detector’s primary calibration was performed. The frequency of re-calibration is a function of the individual application, and should be performed at 12 to 24 month intervals. For process Geiger-Mueller (GM) detectors, a similar, although not as critical (due the wide high voltage operating region) re-calibration process is also required.