ASHRAE Terminology

temperature sensors that utilize the predictable change in electrical resistance of some materials with changing temperature. They are commonly made of platinum. There are two broad categories, film and wire-wound types. Film temperature sensors have a layer of some resistive material, such as platinum, on a substrate: the layer may be extremely thin, perhaps 1 micrometer. Wire-wound temperature sensors can have greater accuracy, especially for wide temperature ranges. The coil diameter provides a compromise between mechanical stability and allowing expansion of the wire to minimize strain and consequential drift.