Multiwavelength pyrometry - An improved method
Abstract
Multiwavelength pyrometry measures simultaneously the temperature and emissivity of a thermal radiator by fitting a large number of radiation measurements to the Planck radiation law relation. It is assumed that a smooth function exists between the spectral emissitivity and the wavelength range of the radiation data. An error analysis shows that the relative errors in the temperature measurements are less than the random relative measurement errors of spectral radiance and that of the calculated spectral emissivity values. The effects of varying different parameters such as the wavelength range, the source temperature, and the number of data pairs on the accuracy of the temperature determinations are studied through computer simulations. It is shown that accuracy increases as the wavelength range is extended toward the peak in spectral radiance and as the number of measured data pairs increases. The experimental confirmation of this technique is presented, showing temperature measurements within 1 percent of the actual temperatures on a platinum surface within a temperature range of 1273 to 1724 K.
- Publication:
-
Optical Engineering
- Pub Date:
- December 1985
- DOI:
- 10.1117/12.7973633
- Bibcode:
- 1985OptEn..24.1081H
- Keywords:
-
- Heat Radiators;
- Optical Pyrometers;
- Spectral Emission;
- Temperature Measurement;
- Computerized Simulation;
- Curve Fitting;
- Emissivity;
- Instrument Errors;
- Instrumentation and Photography