The Research Of Leak Detection System Based On Gas Sensors

As much stricter of safety requirements and complicated for produce structure, air leak testing has played an increasingly important role in guaranteeing product quality, performance and safety use of sealing. Considered of the disadvantages in using leak detection technologies in the process of practical application, including The detection accuracy is easily affected by environmental factors, high costs, difficult operation, immature technology and so on. This paper put forward a method of leak detection based on carbon dioxide gas sensors, meanwhile, the theoretical and experimental research of this leak detection method has been conducted. Major research effort and results are as follows:(1) Based on the in-depth analysis and comparison of the related theory of current leak detection technologies, had put forward the leak detection scheme; designed the principle diagram of the detection method; derived the formula of leakage rate; took the algorithm of optimal weighted data fusion to optimize the experimental scheme.(2) Analyzed the detection programs and contents to develop the general architecture of the testing system. The testing system includes hardware and software parts: Hardware design includes the design and component selection of the pneumatic and electronic control and the mechanical design of the container. Software design includes the parameter configuration, automatic test, data acquisition, data analysis and the other functions.(3) Made experimental study on the leak detection system, detected the standard leak of 100 k Pa test pressure with the reference leak rate of 0.19 ml/min, the measured leak rate of 0.1845 ml/min, the relative error is 2.95%; the relative standard deviation of reproducible test results are less than 10%. Namely the results verify the actual feasibility of the leak detection.Analysis the test results under different pressure and volume to find out the the main factors that affect the detection accuracy and time.By Analysis of the measured data of multiple carbon dioxide gas sensors, Calculated the corresponding standard deviation and the corresponding weights of each sensor. Compared the measured values with new results, figured out that the data fusion methods is practically valuable and significant to improve the accuracy of the detecting system.