Method and apparatus for sensing the condition of a fluid
US5644239A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1994 |
| Grant date | Jul 1, 1997 |
| Priority date | — |
| Expiry date | Apr 15, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/2888
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for determining the condition of a fluid used in a process, such as a lubricating oil used in an internal combustion engine. A sample of the fluid is heated to an elevated temperature, a measurement is taken of an electrical characteristic of the fluid at that first temperature, the fluid is heated still further, and the aforesaid electrical characteristic is measured again. The two measured values of the electrical characteristic are used to calculate a quality parameter which, when compared with quality parameter values corresponding to fluid samples of varying condition, gives an estimate of the relative condition of the fluid sample under test. The test procedure also includes a measurement of the opacity of the fluid sample to visible light, with this measurement being used in conjunction with the calculated quality parameter to more accurately determine the relative condition of the fluid under test. The tester unit may be operated in a stand-alone manner or it may be connected to a computer for storage and display of test results.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.