Rapid acting gas temperature sensor

摘要

A meander-shaped layer of nickel is deposited by evaporation on a ceramic wafer over an intermediate layer of tantalum serving to improve adhesion, and covered by a protective coating of silicon or epoxy resin is used as a temperature sensor in the intake pipe of a supercharged internal combustion engine. The low mass of the sensor element thus provided enables the resistance of the nickel path to follow rapidly, by its variation, the variations of temperature of the intake air. The sensor has a casing made up of two parts, the lower one of which has two connection prongs molded into it, the ends of which are flattened into tabs that are soldered to contact areas of the ceramic wafer. The upper casing portion has a cavity for the ceramic wafer, the lower part of which is filled with a potting compound to protect the solder joints. The width of the nickel paths that provide the temperature sensitive resistance is about 50 mu m and the thickness is from 0.2 to 1 mu m and the resistance may be typically 1000 ohms.