Foil Temperature Sensors
Resistance thermometry is a widely employed method of measuring temperature, and is based on using a material whose resistivity changes as a function of temperature. Resistance Temperature Detectors (RTD’s) have fast response times, provide absolute temperature measurement (no reference junctions are involved), and are very accurate. Measurement circuits are relatively simple, and the sensors, when properly installed, are stable over years of use. Micro-Measurements resistance temperature sensors are constructed much like wide-temperature-range strain gage sensors. The standard sensors utilize nickel or nickel/manganin rolled foil grids, although special-purpose sensors are also available in Balco® alloy or copper foil grids. These temperature sensors are bonded to structures using standard strain gage installation techniques, and can measure surface temperatures from –452° to approximately +500°F (–269° to +260°C). Because of their extremely low thermal mass and the large bonded area, the sensors follow temperature changes in the structural mounting surface with negligible time lag.