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Calibration of acoustic measurands

We measure sound in the free-field and pressure chamber. The calibration laboratory for acoustic measurands stands out for the calibration of measuring microphones, sound level meters and sound level meters.

In addition to manufacturer-independent DAkkS-accredited calibrations, the Testo Industrial Services portfolio also offers verifiable (traceable) acoustic calibrations. The acoustics laboratory is equipped with the latest calibration technology, which enables us to carry out precise and standard-compliant calibrations and to meet the quality requirements of our customers.

Testo Industrial Services is characterised by the wide range of calibration options on the most diverse devices. With the expertise of our technical experts, we cover calibrations of standard instruments such as pistonphones, sound level calibrators, measuring microphones and sound level meters. In addition, we are able to respond with our know-how to customer-specific solutions for, among other things, multi-channel sound level meters or artificial heads. Our DAkkS accreditation in the field of acoustics is recognized for laboratory calibrations.

Your advantage: Our competence

  • A fully equipped laboratory for the calibration of your working standards
  • Adjustment with reference standard microphone according to the substitution principle
  • Standard-compliant DAkkS and ISO calibration of almost all acoustic test equipment possible

Our innovations:

  • Calibration of artificial heads
  • Description of TEDS (Transducer Electronic Data Sheet) devices

Insight into our acoustic calibration laboratory

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Pressure chamber

In the pressure chamber of Testo Industrial Services we can calibrate acoustic measuring instruments such as ½'' pressure chamber microphones or diffuse field microphones. The pressure chamber calibration is possible from 31.5 Hz to 16 kHz in one-third octave or octave steps. Our experts from the acoustics laboratory work with the CS18 SPL calibration system developed by Spektra. The calibration in the pressure chamber is especially designed for the calibration of pressure microphones according to DIN EN 61094-5 and our evaluations are based on DIN EN 61094-4.

Kalibrierung von Messgeräten in der Druckkammer

In the pressure chamber we are specialized in externally polarized and electret microphones of any manufacturer:

  • Brüel&Kjaer - 4192,4193
  • PCB Piezotronics - 378C13,378B11
  • G.R.A.S. - 46A0, 46AD, 46AG, etc.

Free-field chamber

In the free-field chamber of Testo Industrial Services, we can calibrate acoustic measuring instruments such as measuring microphones or sound level meters. The free-field calibration is possible from 125 Hz to 20 kHz in steps of one third or one octave. Our experts from the acoustics laboratory work with a free-field calibration system. The free-field chamber is specially designed for the calibration of free-field microphones and sound level meters according to DIN EN 61094-8 and DIN EN 61672-3. The assessments are carried out in accordance with DIN EN 61094-4 and DIN EN 61672-1 and the frequency assessment in accordance with Z, A, C for sound level meters. We also offer the calibration of artificial heads. The determination and evaluation of the transmission coefficient at frequencies between 250 Hz and 1000 Hz are included in the accredited scope of calibration.

Kalibrierung von akustischen Messgeräten

In the free field chamber, we are specialized in the following measuring instruments:

External polarized and electret microphones from any manufacturer:

  • Brüel&Kjaer - 4188, 4189, 4190, 4191  
  • PCB Piezotronics  - 130A24, 378A04  
  • MTG - MM 210, MM 215, MM 220 
  • G.R.A.S. - 146AE, 40AF, 46AM 
  • OnoSokki – MI-1281, MI-1271 

Class 1 or Class 2 sound level meters:

  • Testo – 815, 816 
  • Brüel&Kjaer 2245, 2250, 2270 
  • Aecom - 01dB  DUO, Fusion 4G, Fusion SLM 
  • NTI Audio– XL2 


Acoustic calibration of class 1 and class 2 calibrators and pistonphones can be performed in the calibration laboratory of Testo Industrial Services. Using the substitution method, we calibrate at fixed points at 250 Hz and/or 1000 Hz with a measurement span of 70 dB to 130 dB and are specially designed in accordance with the requirements of DIN EN IEC 60942.

Kalibrierung von akustischen Messgeräten

We are specialized in the following acoustic calibrators:

Acoustic calibrators and pistonphones from any manufacturer:

  • Testo 0554 0452 
  • Brüel&Kjaer – 4228, 4231 
  • Larson Davis - CAL200, CAL250, CAL150 
  • G.R.A.S. – 42AA, 42AG, 42AP 
  • Castle – dBCal, GA607, GA601 

Success stories

We support you with your requirements and work towards your goals. Here you will find an overview of our most successful customer projects:


Our scope of services for you

Our scope of services includes standard ISO calibrations as well as accredited DAkkS calibrations. Here you will find an excerpt of the services we offer in our laboratories and at your site.

Calibration object: Measuring microphones - Calibration of the amplitude frequency response including determination and evaluation of the pressure-no-load or pressure-operating transmission ratioCalibration DAkkS-accredited*
Frequency range in free field 125 Hz to 20 kHz with a measuring span of -60 dB to 20 dB (referred to 1 V/Pa)
Frequency range with an electro-acoustic coupler 31.5 Hz to 16 kHz with a span of -60 dB to 20 dB (1/2" microphones)
Calibration object: Sound pressure meters - Including adjustment at the reference pointCalibration DAkkS-accredited*
Operating points 94 dB/1000 Hz and 114 dB/1000 Hz for up to three frequency weightings (Lin, A, C)
Amplitude frequency response in the free field at 125 Hz to 20 kHz with a measurement span of 74 dB to 94 dB (referred to 20 µPa) 1000 Hz for up to three frequency weightings (Lin, A, C)
Calibration object: Sound level calibrators / PistonphonesCalibration DAkkS-accredited*
Operating points (fixed values) 250 Hz and/or 1000 Hz of a measuring span from 70 dB to 130 dB**

* in the lab

To read

Take a look at our topic-specific brochures and learn more about calibrating your measuring instruments.