Research And Design Of Microcontroller-based Automatic Thermostat Calorimeter

With the rapid development of science and economy, the quantity demanded for energy sources will increase quickly in our country. So it is more and more widely for the calorimeter to be used in the coal and the electric power industry and so on. At present, the equipments measuring the quantity of heat can not satisfy the need of society. So it is impendent to develop new system with good accuracy and real-time performance.An isothermal automatic calorimeter system with high precision is opened up and designed based on SCM. The design is based on modularized idea which has the advantage of simple structure, low cost, high reliability. The software of the system is fulfilled in C language so that it is easily extended and amended.The high accuracy platinum resistor transducer PT1000 and the new type of singlechip C8051F350 are chosen as the core parts of the system on the base of analyzing the working principle of the calorimeter and the functional modules of the system. And that meets the demand of high accuracy of temperature measurement. C8051F350 device is fully integrated mixed-signal system. It has many functions such as 24-bit A/D conversion, preliminary amplification, filtering and control function etc. Using C8051F350 as the microprocess can not only reduce the system cost but also make the periphery circuit simple to decrease the interference.The error of the platinum resistor is analysed. The optimum design erases the influence of the wiring resistance and rectifies the non-linearity according to two aspects: hardware circuit and software algorithm.Finally, we validate the functions and evaluate the performance of the system. The results prove the system has a better accuracy and precision than the previous system.