Patent · US Expired

Capacitive liquid level sensor

US4977786A · kind A · utility

71Cited by
10References
15Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 18, 1990
Grant dateDec 18, 1990
Priority date
Expiry dateJan 18, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2035/1025
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A capacitance liquid level sensor uses an oscillator and sweeps the oscillator frequency at an ultrasonic rate thereby spreading the frequency spectrum and reducing interference from external radio transmitters and interference to local radio receivers.

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