| 摘要 |
<p>A radiation detector (36) (Figure 2) is housed in a chamber (20a) in a heat conductor (20) which is positioned in a dewar flask (34). A thermo-electric cooler (26) is joined to one end of the heat conductor and a fin heat dissipation device (28,30) is joined to the cooler. A thermistor (24) senses the temperature of the heat conductor. Control means (52) respond to the sensed temperature to operate the cooler to remove heat to stabilize the temperature of the chamber. The assembly extends into a conduit (12) through which flows material, radiation from which is to be detected, the fin assembly (28,30) being exposed to the atmosphere. The detector (36), e.g. a scintillation crystal and a photomultiplier perform better at the stabilized temperature, which may be less than that of the flowing material such as warm oil. <IMAGE></p> |
