| 摘要 |
A method and apparatus for the calibration of a gamma radiation measurement instrument to be used over any of a number of different absolute energy ranges. The method includes the steps of adjusting the overall signal gain associated with pulses which are derived from detected gamma rays, until the instrument is calibrated for a particular absolute energy range; then storing parameter settings corresponding to the adjusted overall signal gain, and repeating the process for other desired absolute energy ranges. The stored settings can be subsequently retrieved and reapplied so that test measurements can be made using a selected one of the absolute energy ranges. Means are provided for adjusting the overall signal gain by varying the voltage supplied to a multiplier phototube included in the instrument, or by varying the gain of attenuators coupled to the output of the phototube. A specific technique is disclosed for making coarse, then fine adjustments to the signal gain, for rapid convergence on the required calibration settings. |
