Study On Optical SF₆Sensor Based On The Differential Detection Technology

SF6gas has good insulating properties and excellent performance of the interrupter, is has been widely used in high-voltage electrical equipment. SF6be used as the insulating medium, enables the device to be miniaturized, and also has high reliability. Filled with SF6gas confined in the high-pressure equipment usually have a certain amount of gas pressure, so it has a higher probability of gas leaks. SF6gas leakage will be the normal working of the equipment impact, while make a threat to the safety of the staff’s life. Therefore, the detection of the concentration of SF6near by the high-voltage electrical equipment is important.By contrast common SF6gas concentration detection method, this design uses infrared absorption measurement method to measure the concentration of SF6gas, designed a high-precision SF6sensor. The infrared absorption method has the advantages of high sensitivity, fast response, affected by environmental interference. Differential detection technology, the overall design of the optical system of the sensor, around the program targeted, selected light sources, detectors, filters and optics, designed dual-wavelength single optical path of the light chamber structure; In order to reduce sensor size, a reflection type optical path adjustment mechanism, optics enable the selection of the light source, filters and detectors have a stable working state, this design produced a smaller deviation. Designed for the operating characteristics of the light source and the detector, the light source driving circuit and a signal amplifying circuit. The light source driving circuit of the electrical modulation of the light source, the working stability is greatly improved; Selection of high-precision signal amplifier chip detector output weak signal amplification, effective suppression of low-frequency noise and improve the measurement accuracy.The sensor developed to be a large number of experiments. According to the measurement needs, build a reasonable experimental platform. By theoretical derivation of the data processing method, the binding test data, given the curve fitting of the sensor. Temperature experiments to study the impact of temperature measurement, obtained the general rules of the sensor measurements with temperature changes. Temperature compensation algorithm by experimental verification, software design, effectively eliminate the influence of temperature measurement; By their repetitive experiments to test the sensor test performance changes over time.According to the experimental results, the paper gives the last part of the performance indicators of the SF6sensor, range0-1000ppm, test accuracy of2%of full scale, with a high stability of work, corresponding speed by measuring the environmental impact of small.