Anemometers are instruments used to measure air and gas velocities in applications ranging from wind tunnel experiments to determine air pollution, smoke extensions and potential wind conditions around buildings, to the assessment of conformance to national and industrial regulations in mines, clean rooms, spray booths, etc. They need therefore to be accurate to better than 10%. Above 2.5 - 3 m/s this is no problem since pitot tubes can be used for their calibration. Below this figure calibration is much more difficult, so much so that a recent survey showed that less than 20% of instruments are accurate to within better than 10% whilst some 40% had errors of over 20%. It is against this background that an intercomparison of anemometer calibration facilities was launched.
Two anemometers, one of the hot wire type and the other based upon a pulsed thermistor, are being circulated to 10 laboratories for calibration in the range 0 - 2.5 m/s at temperatures of 15 - 25 C. Due to faults, repairs and recalibration of the anemometers the termination of the project was delayed. It will be completed 1990.
Funding SchemeCSC - Cost-sharing contracts
RG12 7AH Bracknell