Facility for calibrating anemometers as a function of air velocity vector and turbulence
Iosif Isaakovich Shinder, Michael R. Moldover, James Filla, Aaron Johnson, Vladimir B. Khromchenko
NIST calibrates anemometers as a function of airspeed vector and turbulence intensity (Tu). The vector capability (sometimes called '3D') is particularly important for calibrating multi-hole differential-pressure probes that are often used to quantify pollution emitted by smokestacks of coal-burning electric power plants. Starting with a conventional '1D' wind tunnel, we achieved vector and Tu capabilities by installing translation/rotation stages and removable turbulence generators (grids or flags). The calibration ranges are: yaw angle ±180°; pitch angle ±45°; airspeed 1 m s−1 to 30 m s−1; turbulence intensity 0.07 ⩽ Tu ⩽ 0.25; average data collection rate: 300 points/h at fixed Tu. The system's expanded uncertainties corresponding to 95% confidence level are: airspeed 0.0045 × |V| + (0.036/|V|)2 where |V| is the magnitude of the airspeed in m s−1; pitch and yaw angles 0.3°; and turbulence intensity 0.03 Tu. The airspeed working standard is a laser Doppler anemometer that is traced to SI unit of velocity via a spinning disk. Calibrations are corrected for blockage by the instrument under test and its supports.
, Moldover, M.
, Filla, J.
, Johnson, A.
and Khromchenko, V.
Facility for calibrating anemometers as a function of air velocity vector and turbulence, Metrologia, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932052
(Accessed September 28, 2023)