CRYOSTAT MEASURING WIRE

PURPOSE:To enable heat which penetrates in through a measuring lead wire to be positively removed and discharged out of a cryostat and to prevent a coolant from evaporating uselessly by a method wherein the measuring lead wire is provided inside a coolant gas recovery pipe. CONSTITUTION:A separating plate 13 is provided in spiral to a guide rod 12 formed of material low in thermal conductivity, and a duct 15 is formed between the separating plate 3 and a recovery pipe 14 formed of material low in thermal conductivity. A recovery pipe 11 is provided below a recovery opening 8, furthermore a measuring terminal board 10 is provided adjacent to the recovery opening 8, and a measuring lead wire 9 is provided in such a manner that it is led to the measuring terminal board 10 along a guide rod 12 passing through the duct 15 from the lower part of the recovery pipe 14. Evaporated coolant gas is introduced into the duct 15 through an inner recovery opening 16 located at, the lower end of the recovery pipe 11 and discharged out of a cryostat, through the recovery opening 8 passing through the duct 15. A coolant gas removes heat that penetrates in through the measuring lead wire 9 by its sensible heat while it ascends high in the duct 15. Therefore, cooling coolant can be remarkably lessened in consumption.