High temperature resistance strain gauges

At present all high temperature strain gauges for use at temperatures above 250° C are made from nickel-chromium alloys usually in the region of 25% chromium. Such alloys have the desirable properties of high resistance to corrosion, high electrical resistivity and low temperature coefficient of resistance. Experiments have been carried out that confirm the unsuitability of these gauges for temperatures above 340° C because of order-disorder phenomena. It is shown that satisfactory gauges can be made using alloys based on platinum, containing small percentages of tungsten. Such gauges have been tested successfully at temperatures up to 800° C.