scope:

This part of the Code of Practice deals with the practical application of the flowmeters described in Part 1, Section 1. Information is presented on how to achieve, where practicable, flow measurements with absolute uncertainties of better than +2 per cent.

The flowmeters in Part 1, Section 10f this Code of Practice are:

a) differential pressure meters (orifice plates, nozzles, venturi' nozzles and venturi tubes),

b) turbine meters,

c) positive displacement meters, and

d) variable-area meters.

For these meter types recommendations are made for the following operational features:

i. general,

ii. installation,

iii. flowmeter performance traceability,

iv. computation of flow (rate or volume), and

v. computation of uncertainty related to measurement of flowrate or quantity.

Practices applicable to the various flowmeter types are treated in turn and references are made to relevant existing Standards Specifications where these are available. A description of the procedures for the calculation of the uncertainties of a flowrat,e measurement, with particular reference to differential pressure meters, is presented as Appendix I but the principles of the method may be applied equally to other flowmeter types by substitution of the relevant parameters involved. A bibliography of sources of physical data pertinent to the execution of flow computations is presented as Appendix II.