An automatic calibration method for multichannel photoresistive detection module

It is very important for oil pollution detection instruments to have the function of automatic calibration. During using, the instrument's calibration has high requirements for the medium, personnel level, and operating environment. These requirements will be limitations on device usage. Therefore the research that can make automatic calibration methods more convenient and fast can reduce the cost of the usage of oil detection instruments and improve detection accuracy. Such is a significant work. On the basis of 8-channel detection module, the paper designs an implementation process for automatic calibration. According to the law of particle distribution which is for GBW120083 oil-based standard particulate substance, the paper summarizes the value of particle pulses and the value of pulse amplitude. The model of particle concentration and the value of pulse statistic which belong to different size of particle has been established. The 8-channel detection module tests GBW120083 several times and gets different thresholds and pulse statistics. Fitting the thresholds and pulse statistics into a function, the function can be used to calculate the new thresholds corresponding to the target pulse statistics. These thresholds are the calibration results. During the process of calibration, it is necessary to correct the calibration results by the deviation of pulse statistics. The test data shows that the automatic calibration method designed in this paper. It can reduce the requirements for reference materials and other conditions. The method is flexible, easy to implement, and has good practical significance.