PTC-Temperaturfuehler sowie Verfahren zur Herstellung von PTC-Temperaturfuehlerelementen fuer den PTC-Temperaturfuehler

摘要

A PTC temperature sensor and a process for producing PTC temperature sensing elements from ceramic films for a PTC temperature sensor are proposed. The PTC temperature sensing elements are so designed that the PTC resistor track is hermetically encapsulated with respect to the gas being measured and the ambient air. Ceramic films based on an insulator ceramic, in particular based on Al2O3, and ceramic films based on a solid electrolyte can be used to produce the temperature sensing elements. The PTC temperature sensor according to the invention is distinguished, in particular, by the fact that, while the manufacturing procedure is cheap, it is not subject to aging due to the effect of varying O2 partial pressures, has a high resistance to aging of the resistance characteristic in rich and lean gas mixtures, for example in motor vehicle exhaust gases, at 300 DEG -1000 DEG C. and has a construction free from extraneous potential, is characterized by short response times owning to its low heat capacity and is suitable for incorportion in very narrow housing as a consequence of small dimensions.