Pressure gauge accuracy ranges from grade 4A to D according to ASME 40.1. For a mechanical pressure gauge, accuracy is defined either as a percentage of the full-scale range or a percent of the span. As the accuracy increases, so does the price of the gauge.
Therefore, the application where the gauge is required should be carefully considered before deciding on the accuracy of the gauge.
While requirements differ from one industry to another, the following are general guidelines:
Test Gauges and Standards: 0.25% through 0.10% full scale accuracy.
Critical Processes: 0.5% full scale accuracy.
General Industrial Processes: 1.0% accuracy. Less Critical Commercial Uses: 2.0% accuracy.
