The use of a three dimensional ultrasonic anemometer to measure the performance of clean zone air delivery systems

The Three Dimensional Ultrasonic Anemometer (3DUA) is an instrument that can measure airflow velocities in three axes simultaneously. From the data gathered, airflow direction and air turbulence intensity may be determined. Using a proprietary software package, results are available immediately on-line, in either a tabular or graphic format. This instrument was initially chosen to evaluate the performance of a new cleanroom ceiling system that had integrated the lighting and sprinklers within the filter support grid. Additional work was later performed to evaluate the impact of a membrane ceiling on a turbulent air supply