A laser calibration system for in situ dynamic characterization of temperature sensors

Dynamic calibration of temperature sensors is of crucial importance in many applications where temperature changes quickly. Response time qualification testing of sensors is usually performed by sensor manufacturers by plunge tests into flowing water. “Loop Current Step Response” (LCSR) technique, self-heating index and noise analysis techniques are the current methods used for in situ dynamic characterization of temperature sensors. The dynamic calibration technique using laser as an excitation source has been developed for many applications. Here, a portable dynamic calibration system for in situ calibration is proposed. A high brilliance laser diode heating system is used to generate both step change and ramp change in temperature so as to measure the dynamic response of the sensor. Laboratory tests performed in different environments show the reliability and the advantages of the proposed system. The laser calibration performed with the new portable device gave good results with accuracy levels in comparison with currently available techniques.