ISO 9951:1993, Measurement of gas flow in closed conduits - Turbine meters

Specifies dimensions, ranges, construction, performance, calibration and output characteristics of the turbine meters. Also deals with installation conditions, leakage testing und pressure testing and provides a series of informative annexes A to E including recommendations for use, field checks, and perturbations of the fluid flowing. In many countries, some or all of the items covered are subject to mandatory regulations imposed by the laws of these countries. Where conflicts exist, the mandatory regulations shall prevail.