The Reasearch And Development Of Auto-verification System For Temperature Sensor

With the continuous development of sensor technology, the temperature sensor has been widely used in the process of industrial production. Temperature sensor is one of the important measuring instruments. Correct verfication and calibration for temperature sensor can guarantee the accuracy and unity of the tempaerature value, provide important technical basis for the product quality.In the process of industrial production, thermocouple and thermal resistance is the most widely used temperature sensor. Traditionally, the thermocouple and thermal resistance verification mainly depand on manual operation, such as temperature control,data acquisition and data processing. The traditional verification method has the characteristics of high laborintensity, high workload, low efficiency and large artificial error. At the same time it can’t ensure measured data accurate and reliable.Focusing on the problem of the traditional methods, this paper introduces the industrial thermal resistance, thermocouple temperature measurement principle and calibration methods. Based on the above introduction, this paper analyses the functional requirements and the attainability technique targets of this system. Then it introduces the overall design of system, compostion and structure of system, hardware and software design and implementation. This system consists of data acquisition device,automatic temperature control device, constant temperature equipment, computer,printer and proprietary software. The system data acquisition device is composed of Keithley 2700 data acquisition system and Keithley 7700 switch modules. The system automatic temperature control device is composed of five digital temperature controller made of YuDian, SSR and AC contactor. Using the PC RS-232 serial port connected the PC to the data acquisition device and automatic temperature control device to realize the system measurement automatic data acquisition and thermostatic equipment control.We will use the object-oriented programming method and the C/S structure to design the system software. We will use Microsoft Visual Studio 2010 as the development platform, C#.Net as development language, SQL Server 2005 as database Server to develop the system software. It can realize thermostatic equipment and data- acquisition device auto controlling. It can realize data auto-acquisition, temperature control curve real-time drawing, display and store data. It can calculate the test results, get the test result judgment, generate test record and certificate, can query verification record and certificate, etc.The design of the temperature sensor auto-verification system meets the requires of the verification regulation of industry resistance thermometers, the verification regulation of Working Base Metal Thermocouple and the verification regulation of Working Noble Metal Thermocouple.The system can control temperature automatically,collect data automatically and deal data automatically. The system realizes industrial thermal resistance and thermocouple automatic verification. This system has stable performance, good scalability. Using the system can improve the efficiency of temperature sensor calibration, reduce the labor intensity and human error.