Temperature measurements using multicolor pyrometry in thermal radiation heating environments.

Area of Science:

• Physics
• Materials Science
• Engineering

Background:

• Accurate temperature measurements are critical for thermal-structural experiments, particularly in thermal radiation heating environments.
• Existing methods often struggle with background radiation reflections and unknown emissivities, complicating thermal-structural stress analyses.

Purpose of the Study:

• To develop and validate a multicolor pyrometry technique for precise temperature measurements of diffuse surfaces.
• To eliminate the influence of background radiation reflections and unknown emissivities in thermal radiation environments.
• To apply a least-squares algorithm for enhanced measurement accuracy.

Main Methods:

• Utilized a near-infrared multicolor pyrometer with a spectral range of 1100-2400 nm and a resolution of 6 nm.
• Calibrated the pyrometer's wavelength response, nonlinear intensity response, and spectral response.
• Employed a least-squares algorithm to process calibrated irradiation data for temperature determination.

Main Results:

• Successfully measured the temperature of a graphite sample during heating and cooling cycles.
• Demonstrated that higher temperatures and longer wavelengths are more suitable for thermal measurements in quartz lamp radiation heating systems.
• The developed method effectively eliminates background radiation reflections and unknown emissivities.

Conclusions:

• Multicolor pyrometry, coupled with a least-squares algorithm, offers a valuable and accurate method for temperature measurements of diffuse surfaces.
• The findings are significant for thermal-structural stress analyses in demanding thermal radiation environments.
• Optimized measurement conditions involve higher temperatures and longer wavelengths within the tested system.