抄録
A continuous level indicator of the liquid helium was constructed by using the superconducting Nb-25% Zr wire as a sensing element. The idea of this new device is based on the following facts: (1) There exists a difference of the cooling efficiency between the vapour and the liquid of helium. (2) It is able from this difference to propagate artificially a normal region only in the part of the wire above the liquid level. Thus, the measurement of the voltage across the total length of the wire gives a continuous detection of the liquid level. The main characteristics of this level indicator are summarized as follows: (1) This device is simple in construction and inexpensive. (2) The magnitude of the voltage is precisely proportional to the length of the Nb-25% Zr wire above the liquid level. (3) The response time for a variation of the level is very short.
