For many years, Müller-BBM has operated a calibration laboratory for mechanical quantities - especially for sound pressure and acceleration - for the calibration of our measurement equipment. This calibration laboratory is part of our testing laboratory for sound and vibration, which is accredited in accordance with DIN EN ISO/IEC 17025 (DAR registration number DAP-PL-2465.10). The calibration laboratory is accredited by the Akkreditierungsstelle des Deutschen Kalibrierdienstes (DKD) at the Physikalisch-Technischen Bundesanstalt (PTB) as calibration laboratory for acoustics. The DAR registration number is DKD-K-25201. Müller BBM has a quality management system according to DIN EN ISO 9001.

Independent of the manufacturer, we carry out calibrations of measuring equipment for acoustics and vibrations like microphones, sound level meters, sound calibrators, accelerometers and vibration calibrators. Besides, a large number of amplifiers and filters can be calibrated. It is stated in our current price list for which measuring equipment DKD calibration certificates or factory calibration certificates can be issued. All our calibrations are traceable, i. e. each calibration result can be referenced to national or international norms by a continuous line of comparative measurements with indicated measurement uncertainties.

There are different calibration methods according to the respective test specimen. For sound calibrators and accelerometers, the so-called comparative method is used, i. e. the test specimen is compared with a reference normal and the result of the calibration is determined from the difference between test specimen and reference normal. For the calibration of microphones, a direct calibration is carried out. Here, the test specimen is exposed to a known sound pressure and thus, the calibration result is determined.

For each calibration method, the measurement uncertainty determined according to GUM (Guide to the expression of Uncertainty in Measurement) is stated in the calibration certificate of the respective measurement equipment.

The calibration of your measurement equipment at Müller-BBM will normally not take more than a week. Initially, a receiving inspection of your equipment will be carried out. Afterwards, it will be calibrated and sent back to you together with a calibration certificate. If the equipment is damaged, we will inform you and it will be decided whether the equipment should be repaired at Müller-BBM or - if this is not possible - passed on directly to the manufacturer.