Automatic Calibration System For Thermocouple Based On Virtual Instrument

Thermocouple is the most common temperature sensor. Its application has ever caused great changes in the production technology. As the important means of temperature measurement and instrument industry in the modern society, its precision directly relates the economy benefits of the manufacturers and the users. To ensure the thermocouple's veracity, it must be verified strictly before it is sold, and be calibrated periodically in the process of its use.Its calibrating work is one of the national "mandatory calibration" projects, being in manage by the National Measurement Institute. With the further development and wide application computer to the various fields, the calibrating work for standard thermocouple has being evolved from the past traditional manual operation into the current advanced automation. Computer can complete the calibrating task including sampling, controlling, processing data, displaying, saving and printing calibrating records and certifications. So to summarize, the automatic calibration system not only resolved a series of problems such as detailed data-calculating, major errors, time-losing and so on, but improved the technique. Recently, it has been made successfully by a few domestic corporations. As a sort of merchandise, however, its high cost price on hardware configuration and secret documents on software make it impossible to use in large-scale. Furthermore, with the rapid development of instrument industry, products concerned are researched towards the direction of the integration, great information, programmable control and standardization.Based on above situations, the thesis makes uses of mature computer control technique and data acquisition technique and current abundant software and hardware resources, discusses the research of a new kind of automatic calibration system, uses the advanced DAQ and the powerful function LabVIEW virtual instrument technique, designs the new Automatic calibration system for thermocouple. The system has friendly interface, moreover, it can be transplanted and repeated used. So it is the newest production which combines the computer science and the modern measure and control technique.