| Thermocouple as the main equipment has been widely used in manufacturing enterprises, research institutes and other sectors of the industry in field temperature measuremen, its characteristic is directly related to the quality of the production process control and product quality. However, thermocouple in use is due to the measurement environment, medium composition, temperature and protective insulating material pollution and other factors, after a period of time, the thermoelectric properties will change, especially in the high temperature or pressure and surface temperature conditions, the influence is even more serious.There are many factors that affect the stability of thermocouple, according to the national metrological verification regulations,the new producted thermocouple and using thermocouple shall be for regular and effective verification, only be qualified to continue using. Thermocouple calibration work is done by manual operation traditionally, characteristics with a large amount of raw data, large labor intensity, prone to error, verification time long and so on, and manual operation will bring unnecessary human factors, leading to qualified thermocouple is eventually seized as to be unqualified.Investigated and studied some Co. Ltd. Thermocouple verification system, data transmission uses 485 Bus and temperature control adopts Relay Control. This will affect the data transmission speed, temperature control needs more time. This paper is in use of hardware resources, strictly according to the JJG141-2013 work with the verification regulation of noble metal thermocouple,using the graphical programming language LabVIEW and computer control technology developing friendly man-machine interface. After many times of practical operation, Compared to the certificate issued by the local qualified thermocouple calibration verification,the system has a fast test time, the advantages of high precision temperature control, with high practical value. |
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