Sample injection timer for chromatographic apparatus
US4702115A · kind A · utility
Inventors
Key dates
| Filing date | Feb 25, 1986 |
| Grant date | Oct 27, 1987 |
| Priority date | — |
| Expiry date | Feb 25, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N30/32
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for detecting the injection of a solvent borne sample into the injector port of a chromatograph having a carrier gas flow path for pressurizing the port. The gas pressure in a region adjacent the injector port is monitored. When vaporization of the solvent causes the carrier gas pressure to rise above the steady state value by a threshold amount, a control signal is generated which serves as an accurate time reference for the moment of sample injection into the injector port. The carrier gas pressure is monitored by time averaging the instantaneous carrier gas pressure and differentially sensing the instantaneous carrier gas pressure and the time averaged instantaneous carrier gas pressure. The time averaging is preferably done by flow restricting the carrier gas and accumulating the flow restricted carrier gas in a chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.