Thin filament pyrometry
Thin filament pyrometry (TFP) is an optical method used to measure temperatures. It involves the placement of a thin filament in a hot gas stream. Radiative emissions from the filament can be correlated with filament temperature. Filaments are typically silicon carbide (SiC) fibers with a diameter of 15 micrometres. Temperatures of about 800–2500 K can be measured. History. TFP was first used by V. Vilimpoc and L.P. Goss (1988). A recent paper using TFP is Maun et al. (2007). Technique. The typical TFP apparatus consists of a flame or other hot gas stream, a filament, and a  camera. Advantages. TFP has several advantages, including the ability to simultaneously measure temperatures along a line and minimal intrusiveness. Most other forms of pyrometry are not capable of providing gas-phase temperatures. Drawbacks. Calibration is required. Calibration typically is performed with a thermocouple. Both thermocouples and filaments require corrections in estimating gas temperatures from probe temperatures. Also, filaments are fragile and typically break after about an hour in a flame. Applications. The primary application is to combustion and fire research.