Accession Number : ADD012227

Title :   Organic Semiconductor Vapor Sensing Method.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Wohltjen,Henry

Report Date : 25 Feb 1986

Pagination or Media Count : 8

Abstract : This invention relates to method and apparaturs 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 simplied by constant voltage. One of the sensorsis isolated from vapor exposure to act as a reference for the other sensor which is used for vapor sampling. The output 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.

Descriptors :   *PATENTS, *DETECTORS, *VAPORS, *ORGANIC COMPOUNDS, SAMPLING, SEMICONDUCTOR DEVICES, SEMICONDUCTORS, SEMICONDUCTING FILMS, CONCENTRATION(COMPOSITION), EXPOSURE(GENERAL), RESISTANCE, AMPLIFIERS, INVENTIONS, CIRCUITS, VARIATIONS, FEEDBACK, RATIO, COMPENSATORS, CONSTANTS, TEMPERATURE, VOLTAGE

Subject Categories : Organic Chemistry
      Physical Chemistry
      Electrical and Electronic Equipment
      Test Facilities, Equipment and Methods
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE