Accredited calibration with traceable certification

Barometric pressure sensor calibration – barometer calibration

A pressure sensor (barometer) is used for wind resource assessments in order to measure atmospheric pressure, transforming that into an electrical signal to be recorded by a data logger. The atmospheric pressure is an important measurand, since it impacts the density of the air in motion. Hence, it impacts directly the kinetic energy of the wind, hitting the wind turbine airfoils. Therefore, it is of direct impact to the energy produced by a wind turbine or wind farm (wind park). Even more important is to focus also on accredited pressure sensor calibration.

For a bankable wind energy resource assessment, it is of importance to measure this variable within a qualified, accredited wind resource measurement campaign, in compliance to MEASNET, IEC and FGW standards. The measurement should be taken as close as possible to the projected hub height of the wind turbines as to reduce uncertainties. In addition, the barometer calibration should be ilac-MRA compliant, which is coherent to national standards like DAkkS, N.I.S.T, NABL etc.

The barometer calibration process is the process of measuring the pressure sensor against a normalized reference barometric pressure sensor, in order to give accurate information about the precision of the measurand (i.e. the tested sample barometer sensor). To effectively function, the pressure sensor calibration should be done at regular intervals of about 1 to 2 years, depending on the barometer application and the barometer quality. Only a few high-quality barometric pressure sensors from OEMs like Vaisala, Setra but also from ProfEC Ventus, are very stable and do have a very high long-term stability of only ±0.1 hPa/year, which even yield recommended re-calibration intervals of only about 5 years! This in contrary to the low long-term stability of about ±0.1% / year (of full-scale output, i.e. ~ 0.5hPa for ranges of 600-1100hPa) of several default sensors of lower quality.

Pressure sensor calibration is done as a whole. All the components of the sensor are calibrated together in one line, i.e. transducer, electronics, and cables.

Barometer calibration is done to maintain integrity of the results from the barometric pressure sensor.

ProfEC Ventus with its DAkkS-accredited, ilac-MRA compliant calibration stand offers barometer calibration in ranges of atmospheric pressure levels from 500 hPa – 1100hPa.

Pressure unit conversions relevant for barometer calibration

Conversion Factors for Alternative Pressure Units with reference to hPa
Target	Multiply by
kPa	0,1
mm f Hg	0,75006
in of Hg	0,02953
PSI	0,0145
mbar	1