| 摘要 |
PURPOSE:To enable automatic calibration to be performed by operating a solenoid, before measurement, opening a shutter for a short time, applying irradiated light to a photoelectric doubling tube via an optical fiber. CONSTITUTION:The shutter 9 driven by the solenoid 8 is arranged on an optical axis 2A of an irradiating lens system 2. An input end 10A of the optical fiber 10 is brought to the shutter 9, and an output end 10B is directed to an optical axis of a light collecting lens system 6. Before the measurement, it is ensured that the solenoid 8 is operated and the shutter 9 is operated for a short time. The irradiated light passes the optical fiber 10, and is applied to the photoelectric doubling tube 7 where a current is flowed. Said current is converted to voltage, which is in turn compared with the voltage of a reference power source in a wave height discriminator, and the sensitivity of the photoelectric doubling tube 7 is controlled. After the calibration, the shutter 9 is automatically closed, and the fine grain measurement is started. |
