Patent · US Expired

Non-obstructive thermodynamic fluid flow meter

US4753111A · kind A · utility

21Cited by
10References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 19, 1986
Grant dateJun 28, 1988
Priority date
Expiry dateNov 19, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01F1/6986
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A fluid flow meter using a pair of temperature-variable resistance elements as detectors. Both elements are exposed to the fluid flow and supplied with a series of current pulses. The pulses supplied to one element, the reference element, are of very short duration so as to have no appreciable heating effect; the pulses supplied to the other element are of longer duration and are controlled so as to maintain this element at a fixed temperature differential above the other element, which remains at fluid temperature. The pulse width of the longer duration pulses is a measure of the flow rate of the fluid. Since the relationship between heat dissipated in the element and fluid flow varies with fluid temperature, the voltage pulses across the reference element are used as a measure of fluid temperature to compensate for this variation in calculating the exact fluid flow rate.

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