The Research Of The High-Precision Temperature Control System Based On TEC

An important issue in micro/nano-measurements is the environmental control, including temperature, humidity, cleanliness and vibration. The influence of temperature on the measurement uncertainty is critical for nano scaled dimension. Usually, a clean room has to be built to place in high precision measuring equipment. Its construction cost is high. The indoor activities will also affect the temperature stability. However, that is measurement equipment itself which needs the high precision environment. So it is very import to develop mini-environment for micro/nano-measurements.Traditional temperature-controlled chamber is an integrative body that is composed of a constant temperature chamber and a refrigeration chamber, by natural convection or fans to generate air circulation.This paper develops a new mini-environment that separates the constant temperature chamber from the refrigeration chamber. Any noise caused by the moving parts of the refrigeration chamber can be completely isolated from the temperature chamber. The control system is constituted of a TEC (Thermoelectric Cooler), a programmable power supply, LabVIEW tool, and a PC. Making use of the system identification theory and system identification toolkit of MATLAB, the mathematic model of the constant temperature chamber can be identified. A kind of best control strategy is developed using MATALAB embedded LabVIEW programming. The temperature is detected by five temperature sensors around the inside volume. Experiments show that the temperature fluctuation of a single-point is less than±0.02℃and the whole field is within±0.05℃. The goal of high-precision temperature control is achieved.