Evaporation preventing appts. for liquefied gas reservoir

摘要

A cold end (15) of a cold head (12) of a cryogenic refrigerator (11) is disposed in an upper opening (10) of the liquefied gas reservoir (4), the cryogenic refrigerator being adapted to be put into automatic operation depending on the temperature inside the liquefied gas reservoir, wherein the automatic operation mode of the cryogenic refrigerator can be released by remote control during the use of the detector. The cryogenic refrigerator is put into automatic operation (an alarm having previously issued) when the temperature inside the liquefied gas reservoir increases above a set temperature with the detector being out of use, thereby allowing vaporised gas to be reliquefied with the gas consumption reduced. Bellows (16) prevent vibrations being transmitted from a compressor (13) of the cryogenic refrigerator to the cold head (12). The cold head is mounted on a stand via a horizontal biaxial linear guide mechanism. A liquid level sensor (20) and a temperature sensor (17) are provided for the reservoir (4). The detector is mounted on a cold finger extending from the reservoir (4).