Electrical temperature measuring resistor structure, particularly for resistance thermometers

Abstract

A substrate carrier of electrically non-conductive material has a strip of resistance platinum applied thereto; in order to avoid the use of an intermediate temperature coefficient of expansion matching layer, the substrate carrier, for example of aluminum oxide, beryllium oxide, or a magnesium silicate, has less than thirty parts per million (ppm) Fe, less than 15 ppm Cr, less than 45 ppm Pb and less than 70 ppm Si in a form capable of reacting with platinum, the sum of the impurities by these metals, if all, or more than one are present, not exceeding 20 ppm; the average thermal coefficient of expansion of the substrate does not deviate from the mean thermal coefficient of expansion of the thermometer grade platinum by more than .+-. 30%; the platinum layer has a thickness of from 0.1 to 10 .mu.m, and is applied at a temperature in the range of between about 1000.degree. C to 1400.degree. C during 60 minutes in an atmosphere containing oxygen, for example free air.

Dependencies are inferred from the claim text.