The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 21, 1989
Filed:
Oct. 05, 1988
Heinz Holter, Gladbeck, DE;
Heinrich Igelbuscher, Gladbeck, DE;
Heinrich Gresch, Dortmund-Wickede, DE;
Heribert Dewert, Gladbeck, DE;
Hanns Rump, Unna-Massen, DE;
Other;
Abstract
The present invention relates to a process for indicating toxic substances in air that is supplied to accommodation used for personnel, preferably the cab of a motor vehicle, this having error compensation for humidity and temperature in one or a plurality of semiconductor gas sensors that are used, in which connection the sensor heating voltage is controlled to provide constant heating output and the sensor temperature pick up as well as the necessary amplifier (control stage) used to generate the temperature-varied heating voltage are arranged in a common housing, and that in the area of the sensors this housing is perforated. In order to permit compensation of the toxic substance, temperature, and humidity correlated output signals that are picked up, the present invention proposes that the characteristics curves of the sensor are reproduced in a voltage divider which, outside the sensor and jointly with the sensor forms a voltage divider for a common supply voltage, such that the influence factors compensate each other in equal proportional changes in value of both the sensor and of the outside wiring.