Blog Behind the scenes of a sound level meter calibration

Calibrating sound level meters is no simple task, and one that requires strict control of the environment. In this video, Jesper Bo Vedel, Brüel & Kjær’s Global Calibration Manager takes us through the calibration process and explains its ins and outs.



It is essential that you can trust your measurement data when you are performing sound measurements. At Brüel & Kjær’s headquarter in Nærum, north of Copenhagen, your sound level meters, vibration meters, transducers and other instruments can be calibrated, so that you can be sure that your equipment is always working at its very best and conforms to the relevant standards.

Brüel & Kjær’s Global Calibration Manager, Jesper Bo Vedel, explains why it is so important to calibrate your instrument.
“For customers, it could be a certificate that proves that the instrument is performing in the same way as when it was sold. Or in case of legal metrology – measuring at building sites or roadways – an accredited calibration is a stamp of approval that can be used in legal disputes to convince a court that the measurements are correct, and the instrument is operating correctly,” says Jesper Bo Vedel.

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Calibration isn’t just calibration
Calibration performed in the field versus calibration performed in a laboratory are different in nature. “The difference between a field calibration and a calibration in a laboratory like this one is that the field calibration is merely a check to see that the instrument is working properly. When performing a calibration at Brüel & Kjær, we test a multitude of parameters for the particular instrument. When you perform a field calibration, the process is normally just at one level or one frequency,” says Jesper Bo Vedel.

Rigorous standards for accredited laboratories
Becoming an accredited laboratory puts a great deal of responsibility on the people and methods used. Fortunately, the rules that an accredited laboratory must follow are laid out in the standards that accompany the accreditation.

“We live up to the standards by simply being accredited. The accreditation body DANAK, the Danish accreditation authority, performs regular visits to make sure that we follow every item in the standard. In addition, we also perform internal audits in the laboratory to make sure nothing has moved since the last audit,” says Jesper Bo Vedel.

There’s not much room for creativity in a calibration laboratory with the environmental standards and strict schedules that have to be met.

“The requirements for performing an accredited calibration have a lot to do with environmental conditions in the laboratory. For example, we monitor the environmental conditions and adjust the temperature in some of our laboratories by running water through the ceiling. In addition, the instruments that we use must be calibrated at the intervals that are described in our quality control books,” says Jesper Bo Vedel.


The calibration laboratories at Brüel & Kjær not only perform accredited calibration on Brüel & Kjær equipment, but also on a whole range of other brands that produce class 1 sound level meters and vibration meters. For Jesper Bo Vedel, keeping up with the latest standards and gathering information on international standards is key to ensuring Brüel & Kjær can deliver high calibration standards.

Brüel & Kjær runs nine accredited calibration laboratories worldwide to accommodate international markets. Central for all of them is the turnaround time for customers who rely on their equipment for everyday use.

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