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Alexandrite Effect Spectropyrometer

Our patented alexandrite effect spectropyrometer measure high to ultrahigh temperature from 800 K up to 100,000 K. The spectropyrometer measures the relative spectral power distribution of a radiating body in the UV-VIS-IR wavelength range, integrates the relative spectral power distribution in the whole wavelength range, and determines the temperature using the patented alexandrite effect method. The spectropyrometer can measure any type of radiating bodies: blackbody, graybody, plasma, electric arc, etc. The probe with a heat resistant window can be installed in the most harsh environments, such as combustion chambers, gas turbine, furnace, plasma torch, and etc. The spectropyrometer is invented to measure and control temperature for research, developments, and industrial applications in the fields of, but not limited to, metallurgy, high energy physics, combustion, plasma, and etc.  The spectropyrometer has the functions of displaying the spectrum of the measured target, on-screen spectral correction, temperature scale exchange, signal control and etc.

Patent No.: US 7,004,624 and 7,052,177.


Figure 1. Alexandrite effect spectropyrometer with an optical viewing system.


Figure 2. Measurement screen of the spectropyrometer. 


Temperature Measurement of Thermal Plasmas

The alexandrite effect spectropyrometer is used to directly measure the thermal temperature of an argon gas plasma jet from a 100 kW DC plasma torch, and the directly measured thermal temperature of the plasma is 11178 + 382 K. By using the spectral correction function to delete the spectral lines and to correct its underlying spectrum of the relative spectral power distribution of the plasma jet, the remaining continuum spectral power distribution represents the thermal spectral emission of the plasma jet.  The calculated thermal temperature of the corrected relative continuum spectral power distribution by the spectropyrometer is 10106 K + 345K, which is the true thermal temperature of the plasma jet. The blackbody level (BL) of the thermal plasma jet is defined as the ratio of the true thermal temperature to the directly measured temperature, and the blackbody level is a measure of how well the thermal plasma jet approaches a blackbody. The accuracy of directly measured thermal temperature depends on the blackbody level, the higher the blackbody level, and the higher the thermal temperature measurement accuracy. (Click Here for details)


Thermal temperature measurements of a plasma by the alexandrite effect spectropyrometer and an enthalpy probe

The thermal temperature of a low power rod-type plasma touch is measured by the alexandrite effect spectropyrometer and an enthalpy probe (The measured results by the two instruments are the same. (Click here for details)




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Last modified: 01/22/15.