Design Of Time Constant Measurement System For Thermocouple

With the concept of Industrial 4.0 and Chinese Manufacturing 2025 put forward,great changes have taken place in the field of industrial production automation control.In this context,temperature is an important parameter in the process of automation control,timely and accurate monitoring of temperature is of great significance for the safe and stable operation of equipment.At present,there are many methods for temperature measurement in various fields.Thermocouples have the advantages of simple structure,high measurement accuracy,various types and wide range of temperature measurement.They are widely used in temperature measurement occasions in various industries.With the increasing demand for temperature measurement accuracy and response speed,the dynamic performance testing of thermocouples has become particularly important.The time constant of thermocouple is an important parameter in the dynamic performance index of thermocouple,and its value reflects the dynamic response speed of thermocouple.The smaller the time constant is,the faster the dynamic response speed is,and the more sensitive the perception of ambient temperature changes is.Therefore,accurate measurement of thermocouple time constant is of great significance to improve the stability of automation equipment.In this paper,a set of automatic thermocouple time constant measuring equipment is designed based on the knowledge of automatic control technology,information science and computer technology.The equipment uses mechanical input method to put thermocouples into constant temperature water,uses PCI data acquisition card to collect thermoelectric potential data of thermocouples,and uses the software to process the collected data,to calculate the time constant and send the results to PLC.The research and development of automatic thermocouple time constant measurement equipment is realized,which integrates data acquisition and processing,data storage and automatic classification.This set of equipment can realize the measurement of time constant of various types of thermocouples by adjusting wiring method.Two algorithms for solving time constants are written in the software,and the software is simulated and debugged in the laboratory.After collecting a certain amount of data,the uncertainty analysis and repeatability analysis of the time constants obtained by the two algorithms are carried out.The results show that the resultsobtained by using the iterative method to solve the time constants are more reliable.This set of equipment has the characteristics of simple operation,high measurement efficiency and good repeatability.It plays an important role in improving the detection efficiency and product quality of thermocouple temperature sensor.