Manometer Accuracy

Aneroid Manometers: Properly produced aneroid manometers from reputable manufacturers should provide years of dependable service. In fact, at ADC we randomly bench test our manometers for 30,000 pressure cycles in accordance with ANSI SP10 standards. Government regulations require that both aneroid and mercurial instruments remain within 3mmHg (millimeters of mercury) over their full range when compared to a reference instrument. Many of our premium aneroid manometers are produced to much more rigorous +-2mmHg standards - 33% more accurate that government requirements.

The "oval" or zero point at the bottom of most aneroids (and ALL ADC aneroid instruments) measures the equivalent of 6mmHg across. Thus, when new, so long as the needle is somewhere within that oval, the instrument is accurate.

If the needle rests OUTSIDE the oval when the gauge is disconnected from the inflation system, the unit is in need of re-calibration.

IMPORTANT: Because manometers can be tampered with (and some brands actually facilitate tampering by making them "adjustable") you can NOT be 100% sure that a gauge is in calibration just because the indicator needle rests within the zero point oval. The accuracy assurance is only valid for new instruments from ADC and other reputable manufacturers on NEW, or factory serviced instruments.

ADC manometers are warranted to remain accurate for 10 years, 20 years, or LIFE, depending upon the model. Re-calibration will be performed FREE of CHARGE during the warranty period. Instruments will always be tested free of charge, in or out of warranty.

Mercury Manometers: Unlike aneroid manometers, mercury instruments do not have any mechanical linkages to break, or gears to wear out. As such, once properly calibrated at the factory, mercury manometers will remain accurate so long as the mercury meniscus returns to zero (or within 3mmHg of 0) when the manometer is removed from the inflation system.

Mercury will evaporate and oxidize. As such, additional mercury must be added occasionally to the instrument. The cartridge tube should be cleaned periodically with alcohol using a pipe cleaner soaked in alcohol. Special damping filters located at the top of the cartridge tube must be periodically replaced to ensure smooth mercury flow. Our exclusive unbreakable PVC tubes - with unprecedented 5mm inside bore on most models - are warranted for life against breaking or yellowing. All mercury instruments include a handy service booklet for guidance on cleaning the tube, adding mercury, and replacing the filters.

Should your ADC aneroid or mercury manometer require re-calibration, testing or service, return to:

ADC
Service Department
55 Commerce Drive
Hauppauge, NY 11788

Please allow two weeks to receive your serviced instrument.