Development Of Leak Detection Instrument For Vacuum Membrane Compression Package

When using vacuum hot pressing technology to make composite armor materials,vacuum membrane compression package is a necessary tool to ensure that the prepared materials are in vacuum.However,the vacuum membrane compression package is made of two vacuum films coated with glue,which may have micro leakage holes due to the problem of coating technology.Generally,when the leakage is greater than 0.5mm aperture equivalent,it is difficult to reach a certain vacuum in the vacuum membrane compression package,which will lead to the composite armor material formed by hot pressing can not reach the technical and war indicators.Therefore,it is necessary to detect and identify whether there is leakage in the vacuum membrane compression package to ensure the yield of composite armor materials.Based on the principle of vacuum vessel leakage detection,this paper designs an vacuum membrane compression package leakage detection instrument to detect and identify the simulated aperture of its leakage.The leakage detection instrument is divided into two parts:hardware and software,the hardware part includes ultrasonic sensor,signal conditioning circuit and acquisition circuit,which are used to realize the functions of receiving,amplifying,filtering,acquisition and data interactive transmission with the host computer processing system;The software part takes Lab VIEW software as the development platform,which mainly realizes the real-time processing and storage of leakage ultrasonic signal and the display of signal waveform,spectrum,center frequency and other parameters.Furthermore,in order to solve the problem of accurate identification of leakage aperture of vacuum vessel,this paper adopts an Euclidean distance classification algorithm,which combines the characteristic matrix of leakage ultrasonic signal with Euclidean distance algorithm.Using this algorithm to process the leakage ultrasonic signal can effectively reduce the misjudgment of aperture caused by the randomness of the signal and improve the accuracy and reliability of micro leakage aperture recognition.Finally,the vacuum vessel leakage detection platform is built to simulate the leakage state of the vacuum membrane compression package.Through the test,the vacuum membrane compression package leakage detection instrument designed in this paper can identify the micro leakage hole diameter of 0.4mm ～ 1.0mm under the effective detection conditions,and the identification accuracy is more than 94%.