Method and apparatus for preventing the destruction of an alkali source of a nitrogen-phosphorous detector
US4202666A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 1978 |
| Grant date | May 13, 1980 |
| Priority date | — |
| Expiry date | Feb 24, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/62
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for preventing the destruction of an alkali source in a nitrogen-phosphorus detector by certain reactive and derivatizing reagents encountered in gas chromatography is disclosed. Protection is afforded by lowering the temperature of an electrically heated alkali source during the period in which offensive substances in a gas under analysis are eluted, with the temperature of the source being restored after passage of the offensive substances. The temperature of the alkali source is changed by altering the current through an electrical resistance heater with a temperature control circuit that utilizes a wheatstone bridge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.