Patent · US Expired

Method and apparatus for sensing hydrocarbon gases

US4785658A · kind A · utility

10Cited by
18References
4Claims
0Family size

Inventor

Key dates

Filing dateDec 2, 1985
Grant dateNov 22, 1988
Priority date
Expiry dateDec 2, 2005

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N1/24
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A tubular housing is provided with a conductance sensitive gas detector. Air is drawn by a fan through the housing at a constant rate as the gas detector is traversed across a land area to be studied for reservoirs of hydrocarbon material. The detector is attached to the outside of the vehicle. An output signal from an oscillator whose output frequency varies in response to changes in resistance across two spaced electrodes in the sensor is provided to a recorder within the vehicle. The output frequency is correlated with parts per million of hydrocarbon gas so that meaningful reading can be obtained. An RC timing network with a parallel resistance arrangement with the electrodes provides large changes in oscillator frequency in response to small changes in resistance across the plates.

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