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Sensors made by Innovative Sensor Technology IST AG have been used in space projects since the mid-nineties. In February 2018, IST AG was awarded the ESCC (European Space Components Coordination) qualification for a thin-film based series of platinum temperature sensors. These sensors are currently the only platinum temperature sensors to receive this award from the European Space Agency (ESA). By qualifying, these sensors of IST AG are now the worldwide standard for use in all missions into space.
IST AGs history of space sensors began in the mid 90s with the Rosetta project - a space probe whose lander 2014 arrived in space after more than ten years on the target comet. This was followed by further projects and partnerships, including the collaboration with Tesat-Spacecom. As part of the ESA project for the ESCC qualification of a thin-film Pt temperature sensor, the cooperation between IST AG and ESA began in 2014. Four years later, all necessary developments and tests had been successfully completed – resulting in the sensors qualification by ESA for use in space.
For a long time, wire-wound sensors were used in aerospace, where a thin platinum wire is wrapped around a ceramic plate until the desired resistance is achieved. In space, the sensors are exposed to constant thermal cycles and occasional vibrations. When used in such extreme conditions, wire-wound sensors can quickly fail. For this reason, it was important for the ESA to find a stable alternative that would withstand the enormous temperature fluctuations without imposing any damage. In thin-film based temperature sensors, the platinum resistance structure is firmly connected to the ceramic surface of the sensor. This makes them much more robust and best suited for applications with frequent temperature fluctuations and vibrations.
The sensors of IST AG were subjected to various tests during the evaluation and qualification process. Ultimately, a very good result could be achieved - even at 70,000 cycles from -200 ° C to +200 ° C, the temperature sensors measure remained stable. This proves they are resistant to thermal cycles; the temperature coefficient of resistance (TCR) experienced only irrelevant changes and the sensor proved to be very drift-stable. Further advantages are the small size (L x W x H: 2.3 x 2.0 x 1.3 mm), the light weight and the robustness due to the lack of moving parts.
The qualified sensors are RTDs with different resistances ranging from Pt100 to Pt2000, which can be used in a temperature range from -200 ° C to +200 ° C. The general ESCC specification No. 4006 for temperature resistors as well as for the sensors of the IST AG in particular the detail specification No. 4006/015 applies. Details about the different sensor variants can be found in the ESCC Qualified Parts List (QPL). They are available both as an Engineering Model (EM) or as Flight Model (FM). If necessary, an extension of the wires can be made.