Patent · US Expired

Method and apparatus for measuring the density of fluids

US4956793A · kind A · utility

96Cited by
22References
25Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 24, 1988
Grant dateSep 11, 1990
Priority date
Expiry dateJun 24, 2008

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N25/18
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

The specific gravity, l, of a fluid of interest is determined based on thermal conductivity, k, and specific heat, c.sub.p, of the fluid of interest. An embodiment uses proximately positioned resistive heater and thermal sensor elements coupled by the fluid of interest. Pulses of electrical energy are applied to the heater of a level and duration such that both a transient change and a substantially steady-state temperature occur in the sensor. The k of the fluid of interest is determined based upon sensor output at steady-state elevated temperature, c.sub.p of the fluid of interest is determined based upon the rate of change of sensor output during a time interval of transient temperature change in the sensor, and l is determined from k and c.sub.p.

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