Emissivity constraints for calibration constant models of multi-wavelength pyrometers

The previous true temperature inversion method of multi-wavelength pyrometer based on calibration constant needs to construct a large number of emissivity samples for calculation. It does not fully consider the properties of the measured target. Hence, it is difficult to be applied to high-speed measurement. This paper demonstrates the intrinsic relationship between the calibration constant and emissivity, which is universally applicable to all measured targets. The simulation results show that the calculation speed is increased by 15.47–22.84%, and the calculation accuracy remains unchanged after adding constraints. In practical experiments, the calculation speed is increased by 10.66–18.06%. The experimental results fully show that the constraint method proposed in this paper can effectively improve the calculation speed without changing the accuracy of the constant calibration model. The measurement results of the rocket plume temperature fully reveal the potential application value of the calibration constant constraint algorithm.