Research And Development Of High Precision Air Tightness Test Instrument

With the rapid development of equipment manufacturing industry in recent decades,people pay more and more attention to the sealing performance of various products.Leak testing technology is widely used in industrial production.Covers of the vehicle,machinery,sanitary ware,electronic products,household appliances and medical care,and other areas of the need of leak detection,choose an appropriate detection method has significant practical value and practical significance,but domestic production of detector on the test precision and stability and abroad there is a certain gap.This topic is in response to the requirements of enterprises,in view of the defects and deficiencies of the existing air tightness detection system,put forward a high precision and stability and reliability of the air tightness tester based on the narrow range dual pressure sensor combination development,and the proposed air tightness detection method for theoretical and practical exploration.In this paper,the basic principles of several common air tightness test methods are expounded,and the reasonableness of selecting pressure difference test method for small and medium-sized products is demonstrated.Then,on the basis of the detection method,the pressure difference measurement method based on narrow range double pressure sensor is proposed and its feasibility is analyzed.From this,the overall design scheme of the air tightness detection system is determined,and the design of pneumatic system,mechanical structure,hardware system and software system is completed.In addition to realizing the expected function of detecting the air tightness of the workpiece,the system was also optimized,including the introduction of anti-gas expansion technology and zero-leakage cut-off valve detection technology to eliminate gas series,which greatly reduced the test error and improved the final test accuracy.In addition,through the development of automatic storage,printing and exchange of test data and information,input of product information,intelligent discrimination of test process and results,intelligent modularization of test parameters and data,automatic intelligent processing of test process and test parameters and data is realized.After the successful development of the gas tightness detector,the experimental verification is carried out,and the experimental results are discussed and analyzed.The experimental results show that the test accuracy of the tester can reach 0.2 level,which belongs to the high precision air tightness tester.The ratio deviation rate of verifying repeatability is 0.4% through calculation,and the stability test error is ± 0.203%.In addition,two groups of comparative tests under different test environments are also done to verify the good reliability of the tester.The results show that the system has high precision,stability and reliability,and all the evaluation indexes have reached the expected goals and achieved satisfactory results.