Production and test engineers often know the leak rate of product in bubbles per minute, but do not have an accurate way to convert bubbles to more universal flow numbers such as cubic centimeters per minute. Uson has produced an application note that describes how a mass flow leak tester can be used to establish a quantified leak rate.
Normal leak testers use just a pressure sensor and cannot easily quantify a leak. Users must determine the volume of the products they want to test and then program those numbers into the tester (if possible) to make the tester perform the pressure to flow calculations. Not an easy task.
The flow model testers incorporate two precision sensors: a pressure transducer and a mass flow transducer. To quantify a leak, users simply connect a leaking product to the tester, set it to FLOW mode, and the tester measures the leak in flow units. There is no need to enter the product volume. Results are given directly in flow units that are user selectable.
The full version of the application note may be downloaded here or by visiting www.uson.com and joining the Literature Club.