Thin-filament pyrometry

TFP image in diluted methane flame. Filament spacing is about 10 mm.

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.

See also

• ASTM Subcommittee E20.02 on Radiation Thermometry

References

• L.G. Blevins, M.W. Renfro, K.H. Lyle, N.M. Laurendeau, J.P. Gore, Experimental study of temperature and CH radical location in partially premixed CH₄/air coflow flames , Combustion and Flame 118 (4) 684-696 (1999).
• J.D. Maun, Thin-Filament Pyrometry With a Digital Still Camera, M.S. Thesis, University of Maryland (2006).
• J.D. Maun, Peter B. Sunderland, D.L. Urban, Applied Optics, 46:483-488 (2007).
• W.M. Pitts, Proceedings of the Combustion Institute 26:1171-1179 (1996).
• V. Vilimpoc, L.P. Goss, Proceedings of the Combustion Institute 22:1907-1914 (1988).