The Bubble Immersion leak test method is the simplest and lowest cost leak test method. It can be used on test parts that can be internally pressurized with air and will not be damaged by contact with water. This method, however, suffers from the disadvantage that an operator must pay close attention during the test to visually detect bubbles emitting from the part. Additionally, this method has no way of reliably calibrating the test because operators are typically instructed to reject a test part if bubbles are seen emanating from it.
The sensitivity of this test method his highly subject to test conditions and operator variables. For example, a 0.1 sccm air leak represents one small bubble emanating from a leak defect approximately every 7 seconds.
Checkout the examples below of bubble immersion leak test equipment built by LACO.