Guide tube inserted liquid level sensor

Abstract

This invention relates to a system for sensing the liquid level and coolant properties in a fluid containing vessel by insertion into the vessel of a plurality of matched spaced sensor probes comprising a first and second temperature sensor, the first sensor essentially measuring the media temperature, a heater, an arrangement for applying differential heat between the sensors, the heater and second sensors being thermally connected, all positioned to permit the sensing at the cooling quality of the media present, the heater located directly adjacent the second sensor and adjusted so that when the cooling quality of the normal fluid is sensed the heat generated by the heater and passing into the fluid is virtually completely dissipated and only a small finite differential temperature exists between the sensors and thereby indicates a sub-cooled liquid is present. When fluid is absent and vapor is present a higher and distinguishable differential temperature will exist and the value of the temperature differential is related to the absence of fluid and the cooling properties of the vapor phase that is present is being sensed. In the presence of saturated or boiling liquid there will be virtually no differential temperature and the small differential temperature present in sub-cooled liquid disappears as saturation is approached.

Dependencies are inferred from the claim text.