Patent · US Expired

Apparatus and method for sensing material level by capacitance measurement

US5554937A · kind A · utility

19Cited by
13References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 15, 1995
Grant dateSep 10, 1996
Priority date—
Expiry dateMay 15, 2015

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R27/2605
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A highly accurate system to measure the level of material in a vessel. A probe is provided in the vessel. The vessel and the probe are at different potentials so as to create a capacitance therebetween. The air and materials in the vessel act as dielectrics. As the material level varies, so does the capacitance. This capacitance is subjected to a charge-discharge-charge cycle yielding integrated net neutral charge. The duration of the cycle is compared to a reference time to determine capacitance, which is proportional to the level of material in the vessel.

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