Mullen gauges are available with pressure measurements in PSI, KPA, or Kg/cm2 per sq.cm. All are precisely calibrated and have an external pointer, adjustable with a thumb-screw on the gauge glass. The gauge is calibrated for maximum accuracy over the middle 50% of its scale and use at the extreme ends of the scale should be avoided. Applications involving a pressure range too wide for a single gauge requires the use of Mullen multiple gauge manifolds.

Diaphragm performance is vital to consistent and reliable test results, which is why it should be checked and changed regularly. A Mullen diaphragm height gauge, which allows you to verify distension, will help determine when a diaphragm has exceeded its useful life.

A Mullen Fluid Injector has a piston and shut-off valve to inject fluid and to maintain proper fluid level in the cylinder, thus serving as a fluid reservoir. The fluid injector makes it easy to change diaphragms and ensures testing accuracy.

Manifolds, which are used for mounting multiple gauges on a tester for range variations are equipped with selector and shut-off valves for each gauge.

Aluminum test foils are used to check the accuracy of gauges. Foil sheets, traceable to NIST, are available from 5 to 170 PSI. The tester's performance is checked by bursting all of the aluminum sheets in a packet. If the average burst value lies between the specified range, the instrument is in substantial agreement with institute testers at this burst level. Note: The use of aluminum test foils does not constitute a recalibration of the gauge and does not correspond with NIST standards but serves as a useful precautionary indicator.