Leak masters are a very useful tool. They are calibrated and traceable to standards which can be used to test the validity of a simple leak test or challenge the performance of a complete leak test system. In this regard they differ from the calibration tools that are used to calibrate the leak tester itself.
The calibration of the tester is a matter for a calibration laboratory using the appropriate meters and gauges under standard conditions. Note: At Uson, our calibration laboratory is certified by A2LA to be an ISO 17025 laboratory. The calibration of the leak tester on a regular and documented schedule is desirable because the accuracy and performance of electronic components is known to drift over time.
A leak master is designed to provide a leak of a specified magnitude, under defined conditions of pressure or flow. Thus, it may be used to simulate a leaking part. The correct way to specify a leak master is to define the test pressure, the leak rate and the test medium. The test medium is usually air and would differ from, for example, a leak master created for a helium leak test system.
The leak master itself is validated through the use of traceable instruments that will verify its performance. Once manufactured to the specification requirement, the leak master is issued with a calibration certificate. The certificate should become a part of the user’s quality assurance records and the leak master should be treated and stored in the same manner as other attribute gages. Care should be taken not to drop the leak master as this can cause damage which may change the leak rate.
Because it is a portable quick connect device it can be used to test the integrity of several leak test stations of the same specifications. A technical note is available which provides more detail on the use of leak masters. To get a copy of the technical note simply join our literature club. Join here.