Method and apparatus for measuring temperature using thermocouple
US4990193A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 25, 1988 |
| Grant date | Feb 5, 1991 |
| Priority date | — |
| Expiry date | Aug 25, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K7/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to a method and an apparatus for measuring temperature, using a thermocouple such as a ceramic thermocouple which has no compensating lead wire or has only such a compensating lead wire that is difficult to manufacture. More specifically, the invention is intended to provide a method and an apparatus for accurately measuring temperature even if a temperature difference exists between both cold junctions of the main thermocouple. An auxiliary thermocouple is connected to one leg of the main thermocouple to provide cold junction compensation. Extension lead are connected to both cold junctions to take thermo emf from the thermocouple. The leads are made from a material having a thermo-electromotive characteristic agreeing with the thermo-electromotive characteristic of the other leg at low temperatures at which the cold junction compensation is provided. The invention also provides a converter used to convert the thermo emf of the above-described composite thermocouple into temperature. The converter can set interpolation equations (1) and (2) separately. Equation (1) is used to convert the thermo emf of the auxiliary thermocouple into thermo emf of the main the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.