Influence Of Air Pressure - E+E Elektronik VELOPORT 20 Manuel

Manual VELOPORT 20 english
Correction factor
8.2

Influence of air pressure

The measurement of air velocity using a hot film anemometer is
dependent on the prevailing air pressure p.
The sensors are calibrated in the factory to standard pressure
po=1013.25 mbar. For a velocity measurement at sea level h the
measurement value must be corrected using the barometric
altitude formula.
In practice it is only necessary to multiply the velocity measured by
the sensor vT by a correction factor for the corresponding altitude h
(see Table). The correction factor is a quotient of average air pres-
sure (1013.25 hPa) and actual air pressure, referenced to sea level.
On the instrument the actual air pressure is entered in the lower
menu and in this way the airflow is compensated.
Table: Correction factor as a function of location altitude
page 39