Users should become familiar with ASME B40.100 (Gauges – Pressure Indicating Dial Type – Elastic Element) before specifying pressure measuring gauges. This document – containing valuable information regarding gauge construction, accuracy, safety, selection and testing – may be ordered from: www.asme.org
Pressure Gauge & Range Selection
To ensure proper operation and long service life, the proper pressure range should be selected. For applications with constant, steady pressure, the measured pressure should be no more than 75% of the full scale range of the gauge. For applications with fluctuating pressure, the measured pressure should be no more than two-thirds of the full scale range of the gauge. In general, it is best to choose a range that is roughly 2X the average measured pressure. This gives over pressure protection and the highest accuracy. If you are measuring absolute pressure or differential pressure, a different choice other than a mechanical pressure gauge may be required.