MASS FLOW LEAK TEST METHOD
Like pressure and vacuum decay test methods, Mass Flow leak testing also uses air as the test medium. In production environments it is typically used to test for leaks in the range or 0.5 sccm and larger. This method can be used to measure in-leakage and out-leakage with and without a test chamber, depending on the part configuration. In this method, the leak rate is measured directly using a flow sensor that measures the air flowing into or out of the test volume due to the presence of a leak. This method is more often used for larger leak rates and with larger volume test parts because it does not need to make a pressure drop measurement over a specific test time like the air decay test methods do, thus allowing for faster test times compared to air decay test methods. Calibration of the system is achieved by introducing a calibrated leak standard into the test circuit to simulate a part leaking at or near the reject limit.