| 摘要 |
An electronic device for measuring extremely faint light emissions comprises a photomultiplier tube (1) surrounded by a sleeve (3) made of a material which is a good heat conductor, cooled to a low temperature and insulated from the outside, a thermally insulating and optically transparent lightguide body (5) being stably glued to the photocathode of the photomultiplier tube (1) to receive the light radiation emitted by a specimen (6) to be examined, which is inserted in a cavity (8a) of a supporting structure holding a rotary body (11) which can be turned in front of the lightguide body (5), so as to operate as a shutter for the lightguide in a first turned measurement position thereof to allow measurement of the dark signal and then allow, as the rotary body (11) and the specimen (6) held therein are turned to a second measurement position, to measure the light emission from the specimen (6). <IMAGE> |
