Level meter for molten metal in tube - esp. molten sodium used as coolant in nuclear reactor, where level is monitored by mutual inductance of prim and sec coils wound on tube

摘要

A vertical or sloping tube contains molten metal at a height which is determined by mutual inductance. On the tube is a prim. coil fed with a.c. by a generator and overlapped by a sec. coil connected to a voltmeter; and the two coils are surrounded by a thermally-insulating sheath. The two coils are pref. wound on a double screw thread on the periphery of the tube. The sheath pref. contains an electric resistance heater in mineral insulation located between inner and outer sleeves; and a control circuit is pref. used with the heater to keep the two coils at a desired temp.