ISO 5221:1984

Air distribution and air diffusion — Rules to methods of measuring air flow rate in an air handling duct

Gives different methods of measuring air flow rate in an air handling duct which, without the need of calibration, meet various specific requirements in the field of air distribution and air diffusion. For the purpose of this standard an “air handling duct” is defined as a tight section of ductwork which cross-section may be circular or, excluding for Pitot-static tubes, rectangular.