NBN EN 29104 : 1993

Committees responsible
National foreword
Methods
Introduction
1 Scope
2 Normative references
3 Definitions
4 General testing procedure
5 Evaluation of the effect of an influence quantity
6 Tests for the evaluation of the effects of other
    influence quantities
Figures
1 Sample calibration showing distribution of test
    points
2 Typical circuit arrangements for upstream gate valve
    tests
3 Examples showing the effects of an upstream gate
    valve on three electromagnetic meters of DN 500
    (based on real data)
4 Annular or segmental obstructions used to determine
    the effects of a disturbance in the inlet flow on
    the response of the flow-meter
5 General test circuit
6 Test of the effect of a) mains frequency common-mode
    voltage (voltage applied between the earth of the
    primary and secondary devices) and b) mains
    frequency voltage between neutral and primary earth
    (voltage applied between earth and mains, if
    practicable)
7 Test of the effect of mains frequency voltage
    between earth and output terminals
8 Test of the effect of a.c. currents on earthed
    connection between primary and secondary devices
9 Test of the effect of series-mode signals at the
    supply frequency
10 Test of the effect of stray currents within the
    liquid
Annex
A Bibliography

Describes the evaluation of the performance of electromagnetic flow-meters for liquids flowing in closed conduits. It specifies a uniform procedure to verify the performance characteristics when the flow-meter is subjected to identified influence quantities and methods of representing the results of performance measurements.