Sensor element for a thermal type flowmeter

摘要

A sensor element for a thermal type flowmeter including a ceramic substrate, a thin film, resistor of platinum provided on the outer surface of the ceramic substrate and an outer protective layer of glass provided for protecting the resistor. The glass contains Na2O and K2O in a total amount of up to 3 mol %. The sensor element has a temperature coefficient of resistance approximate to the bulk value of platinum, and can be fabricated with little variation.