BS EN 837-1:1998 pdf free download.Pressure gauges – Bourdon tube pressure gauges – Dimensions, metrology, requirements and testing.
This European Standard specifies requirements for Bourdon tube
indicating pressure gauges, vacuum gauges and
combined vacuum and pressure gauges( compound gauges),with circular, spiral or coiled forms, from 40 to 250 nominal size, and with ranges up to 1600 bar, for the measurement of gauge pressure.
Gauges specified have circular dials with concentric scales for industrial and test use.
The standard includes methods of test for performance to be applied at type approval and production piece tests.
6 Accuracy classes
The accuracy class stating the limits of permissible error is expressed as a percentage of the span.
The following accuracy classes are defined: 0, 1; 0, 25 0, 6: 1; 1, 6; 2, 5 and 4 (see table 1).
For gauges with a pointer stop, the accuracy class will cover 10 to 100 of the range. For gauges with a free zero, the accuracy class will cover 0 to 100 of the range and zero shall be used as an accuracy check pomt.