The Design Of Signal Conditioning And Digital Acquisition System Based On Thermocouple Sensor

The transient temperature measurement technology has been an important research topicat home and abroad. How to accurately measure the transient temperature has a veryimportant significance in our life, industrial,defense and other areas.Because the transient temperature field has many characteristics, such as hightemperature, short duration with high pressure, strong radiation, in this paper, signalconditioning and digital acquisition system based on thermocouple sensor is designed beforethe principles is clear and the technical indicators are developed. It includes signalconditioning and digital acquisition, and focus on the research of the thermocouple signalconditioning. There are three projects in analog signal conditioning in this paper, and aftercommissioning and comparison the results, finally one to achieve requirements of the systemindicator with minimize noise is chosen.The signal conditioning circuit includes several parts of power management, temperaturecompensation, amplification, filtering and bias. The digital acquisition part uses one FPGAchip for control core, and the remaining portion include a power management circuit, A/Dsampling circuit, data storage circuit, USB communication circuit, the clock circuit. There areworks of circuit design, circuit debugging and results contrast in the signal conditioning part.In digital data acquisition part, it has circuit design, simulation and debugging. The use of theprogram is ultimately determined.To verify that the analog part is whether or not to reach the design requirements in actualuse, and the actual indicators is whether or not to match the predetermined technicalindicators, the system is tested in different environments and the data are analyzed. In alaboratory environment, it verifies the various functions of the system. For further in a confined space or a explosion farm environment it verifies the system’s functions andindicators, and proves that the system is more stability and robustness.