thin-filament pyrometry
Image:thin-filament-pyrometry-image.jpg
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 in flames was first used by Vilimpoc et al. (1988).{{Cite journal |last1=Vilimpoc |first1=V. |last2=Goss |first2=L. P. |last3=Sarka |first3=B. |year=1988 |title=Spatial temperature-profile measurements by the thin-filament-pyrometry technique |url=https://doi.org/10.1364/OL.13.000093 |journal=Applied Optics |volume=13 |issue=2 |pages=93–95 |bibcode= |doi=10.1364/OL.13.000093 |pmid=|url-access=subscription }} More recently, this was demonstrated by Pitts (1996),{{Cite journal |last1=Pitts |first1=W. M. |year=1996 |title=Thin-filament pyrometry in flickering laminar diffusion flames |url= |journal=Proceedings of the Combustion Institute |volume=26 |issue= |pages=1171–1179 |bibcode= |doi= |pmid=}} Blevins et al. (1999),{{Cite journal |last1=Bevins |first1=L. G. |last2=Refro |first2=M. W. |last3=Lyle |first3=K. H. |last4=Laurendeau |first4=N. M. |last5=Gore |first5=J. P. |year=1999 |title=Experimental study of temperature and CH radical location in partially premixed CH4/air coflow flames |url=https://doi.org/10.1016/S0010-2180(99)00023-1 |journal=Combustion and Flame |volume=118 |issue= |pages=684–696 |bibcode= |doi=10.1016/S0010-2180(99)00023-1 |pmid=|url-access=subscription }} and Maun et al. (2007).{{Cite journal |last1=Maun |first1=J. D. |last2=Sunderland |first2=P. B. |last3=Urban |first3=D. L. |year=2007 |title=Thin-filament pyrometry with a digital still camera |url=https://doi.org/10.1364/AO.46.000483 |journal=Applied Optics |volume=46 |issue=4 |pages=483–488 |bibcode= |doi=10.1364/AO.46.000483 |pmid= |hdl=1903/3602 |hdl-access=free }}
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.