Network Temperature Switch Automatic Calibration System Design

Temperature switches are widely used in household appliances and industrial electrical equipment,to protect the normal operation of electrical equipment.In addition,some temperature switch applications and sophisticated lab environment,the requirements for temperature switch values are also increasing.The ability to accurately calibrate the temperature switch is also becoming increasingly important.General Administration of Quality Supervision,Inspection and Quarantine of the People’s Republic of China(AQSIQ)is working on the temperature parameter calibration specification for temperature switches.The results of this paper will also provide some theoretical and data base for it.This paper designs a system to calibrate the temperature switch.In order to improve the temperature switch calibration efficiency and calibration accuracy,We have done a lot of calibration experiments.Specific contents and results are as follows:(1)Check the temperature switch related literature and information.Learn the working principle and calibration process of the temperature switch.On its basis,we propose to design a network of temperature switch automatic calibration system.(2)The temperature switch calibration system requirements precise and stable environment.We use second-class standard platinum resistance thermometer as the standard temperature sensor collection.And we use the constant temperature oil tank to calibrate the temperature switch.The system can control the rate of oil temperature between 0.1℃/min and 2℃/min,to ensure the accuracy of the temperature switch parameters collected.The communication protocol between the lower computer and Host Computer is RS-232 and RS-485 serial communication.Wi-Fi network can also be used with the Lower Computer to establish a connection.(3)Based on PLC automatic control technology and LabVIEW software development technology,developed a network temperature switch automatic calibration system.This system can do temperature acquisition,switch data collection,data processing,database and reporting functions.(4)After the system is commissioned,a series of experiments on the temperature switch are carried out based on this system,and the uncertainty of the calibration system is analyzed and evaluated.The results show that this set of calibration system to achieve the desired goal,has been put into use,and achieved good results.Finally,the experiment is carried out on the possible effects of different temperature rise and fall rates in the calibration environment,and a correction method is proposed.