NF EN 24185 : 1994

National foreword
Cooperating organizations
Method
1 General
2 Principle
3 Apparatus
4 Procedure
5 Calculation of flow-rate
6 Calculation of the overall uncertainty of the
    measurement of the flow-rate
Annexes
A Corrections on the measurement of filling time
B Density of pure water
C Definition of terms and procedures used in error
    analysis
D Student's t-distribution
Table
1 Values of Student's t
Figures
1A Diagram of an installation for calibration by
    weighing (static method, supply by a constant level
    head tank)
1B Diagram of an installation for flow-rate measure by
    weighing (used for an hydraulic machine test; static
    method, supply by a constant level head tank)
1C Diagram of an installation for calibration by
    weighing (static method, direct pumping supply)
1D Diagram of an installation for calibration by
    weighing (dynamic method, supply by a constant level
    head tank)
2 Examples of diverter design
3 Operational law of diverter
4 Time metering for a diverter the operation law of
    which is identical in both directions
5 Example of error distribution in calibration of
    weighing machine
6 Typical graph used in evaluation of (ER)p for a
    diverter system
7 Plotting of results of diverter timer actuator as
    given in A.1.2

Describes a method of liquid flow-rate measurement in closed conduits by measuring the mass of liquid delivered into a weighing tank in a known time interval. May be applied to any liquid provided its vapour pressure is such that any escape of liquid from the weighing tank by vaporization is not sufficient to affect the required measurement accuracy. Closed weighing tanks and their application to the flow measurement of liquids of high vapour pressure are not considered. Does not cover corrosive or toxic liquids.