Design And Realization Of Intelligent Integration Temperature Transmitter

Temperature detecting is directly related to energy conservation, product quality, safety processand, as well as production efficiency etc. important technical economy indexes. Traditional temperature meter bears disadvantages such as big quantity of compensation lead wire, long transmission distance, and with heavy maintenance tasks, as well as non-smart. As the new generation of temperature meter, smart integral temperature transmitter is with high precision, smart communication, detecting element integral installation, field4-20mA standard signal, easy maintenance, and good stability, as well as high reliability etc. features. This smart integral temperature transmitter is widely used formeasurement and control in the field of national defense, petrochemical, metallurgy, and light industry, as well as electric power etc. Design of smart integral temperature transmitter is helpful for independent innovation ability promotion, and with positive reality and engineering significance.This paper is to describe temperature detecting principle in details, and to put forward general design scheme for smart integral temperature transmitter. Hardware is designed with circuits of temperature detecting, single-chip microcomputer control, A/D, EEPROM interface, USB communication interface etc., with XTR108chip as measurement process core, C8051F340single-chip microcomputer as transmitter control core, AD421and A5191chips as for (+HART) signal process core. Isolation circuits composed of analogue contactors are also designed between single-chip microcomputer and communication interface, which reduce digital interference to minimum. Software is designed with single-chip microcomputer main program, calibration&range setup, temperature detecting, data process, modules for display and keyboard, USB, current output and HART communication. Functions such as range setup, digital calibration and meter information input etc. are implemented by smart integral temperature transmitter with precision higher than0.1%.Smart integral temperature transmitter passes performance test carried out by factory, which proves that the design is with reliable hardware and reasonable software structure, achieving expected goal of high precision, smart type and high performance price ratio and can be applied in industrial process widely.