Research Of Remote Calibration System For Resistance Thermometer

Resistance thermometers are temperature measurement devices which arewidely used in industrial production, but theirs performance are easily changed by theenvironment, so they must be periodically calibrated. Remote calibration is animportant research field in metrology. Combined with network technology to realizeremote calibration for resistance thermometer can effectively improve the traditionalcalibration method such as long calibration interval, difficult management, lowefficiency and shortcomings, but it also brings problems such as traceability andquality control. This paper based on JJG229-2010Verification Regulation ofIndustry Platinum and Copper Resistance Thermometers, to ensure the system’straceability, quality control and reliability, and design and implement theremote calibration system for resistance thermometer. The main works of thispaper’s research are as follows:1. This paper reviewed the domestic and foreign research situation of remotecalibration. Problems in remote calibration such as traceability and quality control areput forward. Combined with network technology, the traditional method of calibrationfor resistance thermometers was improved, and an implementation scheme of remotecalibration system of resistance thermometers was put forward.2. Design the remote calibration system for resistance thermometers according tothe implementation scheme. By using ARM9and embedded Linux operating systemto realize the scene of the calibration equipment supervisory control and dataacquisition, a controller for field calibration is designed. By combining C/S and B/S,a new network structure is designed. By using MFC, software for client and server isprogramed. And by using Microsoft SQL Server, a remote database is built. Thesystem realized a lot of functions such as user management, video monitoring,database management, etc. And by the form of web server data forwarding, theremote real-time monitoring and network data transmission from calibration master to calibration site are realized. Verified by experimental test, the system is safe andreliable.3. In consideration of the characteristics of small sample quantity in resistancethermometer’s remote calibration, system uses Bayesian methods for uncertaintyevaluation. According to the Bayesian method in the condition without priorievaluation is difficult to evaluate, a solution by collecting additional data is putforward. By comparing with GUM method, the experimental results have proved thatthe new method is feasibility and accuracy to evaluate the uncertainty of remotecalibration system for resistance thermometer.