Research On Powder Temperature Measurement System Base On Multi-Spectral Thermometry

Temperature is one of the important parameters which determine the physical state. Temperature measurement and control play a very important role in national defense and military and industrial and agricultural production. According to the demands of the Institute of Applied Physical and Chemistry of Shannxi province, the Institute of Automatic Detecting and Process Control System (D&CS) of Harbin Institute of Technology has taken on the development of "the measuring equipment of powder temperature".Flame temperature of powder often reflects some of characteristics of conbustion. Developing the research on powder temperature measurement system has a practical significance on promoting the progress of powder technology and improving the devising level of weaponry of our country.The flame of powder has characteristics as absorption peak, high temperature, short continuance ,ect. The method, introduced in this dissertation, which is used to achieve temperature measurement of the flame of powder is multi-spectral radiation thermometry, which has an unparalleled advantage over other emissivity compensating methods and may gain the emissivity and temperature of the object. Multi-spectral temperature measurement method can be widely used in rapid measurement of high-temperature for it is not affecting target temperature field, fast response and without measurement ceiling and so on.The main work contains the design and debug of hardware system and software system, the calibration of the pyrometer and the acceptance tests. The hardware system can be divided into two parts: the optical channel and the circuit. The radiant energy sent by the powder is sampled by lens, transmitted through fiber, dispersed by prism and then reaches the photodetector, where it is transformed into electrical signal. The signal transits preamp, AD conversion circuit and is collected by data synchronous acquisition card BC426. The acquired data will be stored and processed in computer. The software is programmed by LabVIEW8.6. It is easy to learn and can make program development faster. Calibration includes two sides: pyrometer wavelength function calibration and temperature calibration.This system differs from the past similar equipment in many ways. Different powder has different characteristic absoption peak.According to different powder,staff can remove some of measurement chanels.Using near-axis design and prism dispersal in optical channels to reduce the energy loss. Those channels are independent with each other, so there is no spectrum aliasing phenomenon. Data acquisition system that includes high-precision card BC426 which integrated with 16-bit ADC, works steadily and has a strong anti-interference capability that makes great improvement to the system in speed and precision. The software is programmed by LabVIEW8.6, which make hardware drive perfect and the data-processing much powerful.