Novel method for the realization of small differential pressures between 1 Pa and 1 kPa

Abstract

This paper reports a novel method for the realization of small differential pressures in the range of 1 Pa and 1 kPa by using a precision wind tunnel with Laser Doppler Anemometer (LDA) and a Prandtl tube. The LDA system measures the wind speed of the precisely controlled wind tunnel and provides traceability to SI. A Prandtl tube immersed into the wind tunnel, relates the well-controlled airflow speed to the pressure difference of total pressure and static pressure at the point of measurement. Experiments have been performed in the range between 0.5 and 60 m/s air velocity corresponding to about 150 mPa and 2.2 kPa. The measurement uncertainty of the generated differential pressures between 1 Pa and 1 kPa are calculated to be around 0.8% (k = 2).