2 Air Flow Measurement Procedure footnote
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC/Circular.729 – Design Guidelines and Operational Recommendations for Ventilation Systems in Ro-Ro Cargo Spaces – (Adopted on 4 July 1996) - Part 2 - Operational Recommendations for Minimizing Air Pollution in Ro-Ro Cargo Spaces - Appendix 2 - Measurement of Air Flow - 2 Air Flow Measurement Procedure1

2 Air Flow Measurement Procedure footnote

 For supply or extract grilles the anemometer is used as follows:

The gross grille area is divided into 150-300 mm squares, depending upon the size of grille and variation in the velocity pattern.

The anemometer is held at the centre of each square with the back of the instrument touching the louvres which must be set without deflection.' The instrument will give an immediate reading of the indicated velocities at the centre of all squares have been recorded, the average value of these velocities should be calculated; this average value is the 'indicated velocity' for the whole grille.

This method will normally provide repeatable results. In practice the only inconsistency it is necessary to consider is where the grille damper is well closed down, thereby causing the air to strike the anemometer vanes in separate jets rather than with uniform velocity. In this case a hood may have to be used with the anemometer.

Parent topic: Appendix 2 - Measurement of Air Flow
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