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:
Feb. 14, 1989
Filed:
Jan. 21, 1987
Dragerwerk Aktiengesellschaft, Lubeck, DE;
Abstract
A method detects the proportion of combustible gas in a mixture of air with a measuring device which operates by both the heat-tone and heat-conductivity methods. The method permits measurement in the full concentration range with a high degree of accuracy and the lowest possible energy consumption. The measuring device is made small and light and its sensor has a long service life. The method uses one single sensor which operates at a low temperature in the heat-conductivity mode or alternatively, catalytically active at a higher temperature in the heat-tone mode. If the measurement provides a result below a reference value or within a reference value window, measurement continues in the more accurate heat-tone mode. When the gas concentration increases during measurement, in order to avoid ambiguity of the measuring signal and damage to the sensor above a load-limit value, measurement again takes place in the heat-conductivity mode by reducing the temperature of the sensor.