Establishment and Uncertainty Analysis of Dynamic Model of Thermocouple Sensor Under Laser Pulse Excitation

Dynamic calibration is essential for reducing measurement errors when using thermocouple sensors for dynamic temperature measurement. This paper proposes and implements a complete analytical framework encompassing time-domain dynamic calibration to frequency-domain uncertainty quantification. A laser-based dynamic calibration system was employed, and the particle swarm optimization (PSO) algorithm was used to identify the parameters of the thermocouple dynamic model, with its parameter configuration systematically investigated. A K-type thermocouple was dynamically calibrated to validate the proposed method. The innovation of this framework lies not only in obtaining the optimal dynamic model but, more importantly, in the systematic propagation of the statistical uncertainty of the model coefficients to the sensor’s frequency-domain characteristics, which enables the quantification of confidence intervals for the dynamic response. Furthermore, the impact of frequency-domain uncertainty on time-domain waveform reconstruction fidelity was analyzed, and based on this, the usable dynamic bandwidth of the sensor was defined. This approach provides a comprehensive analysis tool for evaluating the dynamic performance and reliable application of thermocouples.