| 摘要 |
Method for luminosity measuring advantageously in TLD evaluation equipment in the course of which a photomultiplier current is made proportional with light intensity and said current is measured; and sensitivity control of photomultiplier is conducted by varying its supply voltage if the current is above a given level. This change is stored. The said measurement is conducted in analog or digital form. Circuit arrangement to implement the procedure has a photomultiplier tube (11), high voltage power supply and level sensor, the input of the photomultiplier tube being connected to the output of the high voltage power supply, the output of the tube connected to the input of the level sensor characterized so that this circuit arrangement has a control unit (14) whose input is connected to the output of the level sensor (12), and its output is connected to the input of the high voltage power supply. The level sensor may comprise analog to digital converter (21), digital to analog converter (22), comparator (23) and digital counter (24) connected in series to analog to digital converter (21), decimal counter (25) and control register (26) connected in series. The control unit (14) has a reference source (27) and calibrating divider (28), the inputs of which are connected to the output of the reference source (27). The calibrating divider has three resistors (R1, R2, R3). |
