Organic semiconductor vapor sensing method
US4572900A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 25, 1984 |
| Grant date | Feb 25, 1986 |
| Priority date | — |
| Expiry date | Apr 25, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/126
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus to automatically compensate for temperature variation in a vapor detection system. In one embodiment, two identical organic semiconductor film sensors in close thermal contact with each other are used in the feedback circuit of an inverting amplifier supplied by constant voltage. One of the sensors is isolated from vapor exposure to act as a reference for the other sensor which is used for vapor sampling. The output of the inverting amplifier provides an indication of the presence and relative concentration of vapor exposure. Variation in sample sensor resistance due to a change in temperature is accompanied by the same corresponding change in the reference sensor, which stabilizes the ratio of the feedback circuit resistances and therefore the gain of the inverting amplifier to exactly compensate for the temperature induced resistance variations automatically.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.