BS ISO 3354:2008

Foreword
1 Scope
2 Normative references
3 Terms and symbols
   3.1 Terms
   3.2 Symbols
4 Principle
   4.1 General
   4.2 Measurement of the measuring cross-section
   4.3 Measurement of local velocities
   4.4 Location and number of measuring points in the
        cross-section
5 Description of the current-meter
6 Requirements for the use of current-meters
   6.1 Selection of the measuring cross-section
   6.2 Devices for improving flow conditions
   6.3 Calibration of the current-meter
   6.4 Limits of use
   6.5 Inspection and maintenance of current-meters
7 Setting of current-meters into the conduit
   7.1 Setting of current-meters
   7.2 Mounting in a circular cross-section
   7.3 Mounting in a rectangular cross-section
8 Determination of the mean axial fluid velocity by graphical
   integration of the velocity area
   8.1 General
   8.2 Circular cross-sections
   8.3 Rectangular cross-sections
9 Determination of the mean axial fluid velocity by numerical
   integration of the velocity area
   9.1 General
   9.2 Circular cross-sections
   9.3 Rectangular cross-sections
10 Determination of the mean axial fluid velocity by
   arithmetical methods
   10.1 General
   10.2 Log-linear method
   10.3 Log-Chebyshev method
11 Uncertainty in the measurement of flow-rate
   11.1 General
   11.2 Sources of error in local velocity measurements
   11.3 Sources of error in estimation of flow-rate
   11.4 Propagation of errors
   11.5 Presentation of results
   11.6 Calculation of uncertainty
Annex A (normative) - Measuring sections other than circular
        or rectangular sections
Annex B (normative) - Corrections for blockage effect
Annex C (normative) - Recommendations for the selection of
        the type of current-meter and mounting strut
Annex D (normative) - Example of measuring point
        distribution along a radius for velocity
        measurement in a conduit of circular
        cross-section in the case of the graphical
        and numerical methods
Annex E (normative) - Determination of boundary layer
        coefficient, m, for extrapolation near the
        wall
Annex F (normative) - Definition of terms and procedures
        used in the uncertainty calculation
Annex G (normative) - Student's t distribution
Annex H (informative) - Examples of values of component
        uncertainties
Annex J (informative) - Example of calculation of the
        uncertainty in the flow-rate measurement
        using current-meters

Describes the technology and calibration of propeller-type current-meters, the measurement of local velocities and the calculation of the flow-rate by velocity integration.

This International Standard specifies a method for the determination of the volume flow-rate in a closed conduit by means of the velocity-area method using propeller-type current-meters under the following conditions: the velocity distribution is regular (see 6.1.2); the fluid is water which is clean or considered to be clean1); the conduit is full; the flow is steady2). It deals in particular with the technology and calibration of propeller-type current-meters, the measurement of local velocities and the calculation of the flow-rate by velocity integration.