Grain boundary sliding in platinum resistance temperature sensors

After the Hughes Aircraft report published in ISFTA, 1986, entitled Failure of Platinum Resistance Temperature Sensors, further investigations have been carried out by some European companies on the 118MF probes with important consequences. The aim of the present paper is to asses the importance of the platinum wire metallurgical behaviour - grain growth and grain boundary sliding) - and to: - Try to propose a specific lot acceptance test for this type of product. - Define a failure criteria for the proposed testing, currently not available. (Particularly SEM inspection on wires). - Look for alternative solutions and the impact of these alternatives to space applications.