Tutorial 1.1

Monday, 3 May 2021, 10:00 - 11:30


Leak Test of encapsulated Sensor Systems with the Test Medium Compressed Air


Presenter: Joachim Lapsien, CETA Testsysteme GmbH, Hilden (Germany)

Due to the wide range of industrial applications of sensor systems, a multitude of requirements are placed on this component. These include tightness against dirt and moisture. The penetration of liquids can lead to serious malfunctions and thus of the connected electronics. Therefore the leak test as a routine test in the production line is of special importance. The use of the test medium compressed air in industrial production processes are part of the 100% inline leak test is widespread. Compressed air can be used down to an air leakage rate of 10-3 mbar*l/s (depending on the test part volume). An air leakage rate to 10-2 mbar*l/s is usually assumed to be watertight.


Typical examples of automotive sensors which are tested with compressed air are oil pressure sensors, ABS sensors, level sensors. Encapsulated sensor systems cannot be filled with compressed air directly. They are tested in a test hood which is pressurized. The pressure change inside the test part due to leakage is detected with high resolution. In order to achieve the best possible resolution, it is necessary that the hood circumvents the outer contour of the test part as closely as possible. Hereby the dimensional tolerances of the test part have to be considered. The leak test of encapsulated products consists of two steps: 1. Check that the test part does not have a gross leak, 2. Fine leak test by measuring the pressure decav. As a rule, the differential pressure method is used for fine leak test.

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