Patent · US Expired

Liquid level detecting apparatus

US4135186A · kind A · utility

28Cited by
4References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 23, 1977
Grant dateJan 16, 1979
Priority date
Expiry dateFeb 23, 1997

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01F23/247
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A liquid level detecting apparatus comprises a thermistor adapted to generate heat by current flowing therethrough, wherein the liquid level is sensed by detecting a current value at the thermistor which varies in dependence on a variation in temperature of the thermistor, which temperature in turn varies in dependence on whether the thermistor is immersed in the liquid or exposed to air. A relay coil is provided in series to the thermistor and disposed within a casing together with the latter so that the variation in temperature of the liquid may be transmitted to the relay coil, wherein the variation in the current value at the thermistor caused by the temperature variation of liquid is corrected by the variation of the resistance of the relay coil.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.