Liquid level sensor

Claim 1

In a liquid metal level containment system, a combination of, a container and liquid metal therein, a closed end tubular protective housing extending into the liquid metal and a continuous elongated liquid metal level mutual inductance probe to provide a continuous, substantially linear liquid metal level indication, said probe having a continuous primary winding and a continuous secondary winding wound coextensively about the longitudinal axis of said closed end tubular protective housing, said coextensively wound primary and secondary windings being inserted in the closed end tubular protective housing and isolated from direct contact with the liquid metal contacting the closed end tubular protective housing, the primary and secondary windings of the elongated liquid metal level mutual inductance probe consisting of multiple coil turns, changes in mutual inductance occuring in response to changes in the level of the liquid metal producing an output signal from said secondary winding indicative of the level of liquid metal in said containment, the coil turns per unit length of said coextensively wound primary and secondary windings at either or both ends of said elongated liquid metal level mutual inductance probe progressively increasing over an end portion of said probe toward the end of said probe, the number of coil turns per unit length in said end portion being greater than the coil turns per unit length in the remaining portion of said elongated liquid metal level mutual inductance probe.

Claim 7

A method for improving the linearity characteristics of an end portion of an elongated liquid metal level mutual inductance probe comprising primary and secondary coil windings wound coaxially and coextensively in an elongated configuration and being inserted within a closed end tubular protective housing immersed in a liquid metal wherein said probe develops an output signal in response to the magnitude of the mutual inductance related to the level of said liquid metal, comprising the step of, winding a progressively greater number of coil turns per unit length of said coaxially and coextensively wound primary and secondary coil windings in the end portion of said elongated liquid metal level mutual inductance probe nearest the closed end of said closed end protective housing, the number of coil turns per unit length in said end portion being greater than the number of coil turns in the remaining portion of said probe to increase the mutual inductance characteristics of the end portion of said probe closest to said closed end.

Claim 8

A method for improving the linearity characteristics of an end portion of an elongated liquid metal level mutual inductance probe comprising primary and secondary coil windings wound coaxially and coextensively in an elongated configuration and being inserted within a closed end tubular protective housing immersed in a liquid metal wherein said probe develops an output signal in response to the magnitude of the mutual inductance related to the level of said liquid metal, comprising the step of, winding a progressively greater number of coil turns per unit length of said coaxially and coextensively wound primary and secondary coil windings in the end portion of said elongated liquid metal level mutual inductance probe nearest the closed end of said closed end protective housing, the number of coil turns per unit length in said end portion being greater than the number of coil turns in the remaining portion of said probe to increase the mutual inductance characteristics of the end portion of said probe closest to said closed end.