Microphones & Preamplifiers Calibration

Long-term Quality Assurance of Measurement Results

Professional transducer calibration is a prerequisite for assuring the quality of your measurement results in the long term. HBK performs calibrations in service centers accredited by national accreditation bodies according to EN17025 or certified under ISO9001.

For microphones and preamplifiers, Brüel & Kjær provides two primary calibration services: accredited calibration and traceable calibration. These services include accreditation for selected countries.

Sensitivity of microphones is measured at 250 Hz. Standard frequency range for calibrations is from 20Hz to 20kHz in coupler comparison calibrations, and up to 200 kHz using electrostatic actuator method (IEC 61094-6). Low-frequency calibrations are available in the range from 0.1 Hz to 250 Hz.

For TEDS microphones, the calibration values are loaded into the microphone as part of the calibration.

An accredited certificate will be accepted without discussion from your customers or auditing authorities. We can provide the following types of accreditation for Brüel & Kjær measurement microphones and microphone preamplifiers:

• DANAK (English certificate)
• A2LA (English certificate. Includes frequency response curve)
• DAKKS (German certificate)
• COFRAC (French certificate)
• ENAC (Spanish certificate)
• NATA (English certificate)

Initial calibration

Most types of microphones from Brüel & Kjær are delivered with the manufacturer’s measured calibration data. To start the accredited calibration history from day one, we recommend that you take advantage of our accredited-calibration services when you purchase your new microphone and preamplifier.

Re-calibration

Brüel & Kjær recommends annual re-calibration to provide data for an unbroken calibration history to use as a reference, either for internal requirements, for auditing required by authorities or at the request of your customers. The shorter the period between calibrations, the lower the risk of questionable measurements.

For non-TEDS microphones, we recommend you include your preamplifier to ensure there is no unknown deviation in your instruments.

Measurements

Calibration of microphones is performed at 250 Hz. Measurements are conducted according to IEC 61094 and to the manufacturer’s specifications.

For TEDS microphones, the calibration values are loaded into the microphone.

Accredited calibration with frequency response is available with an A2LA certificate.

Measurements are traceable to institutions such as DPLA, NIST, NPL and PTB.

Certificate

With the certificate you receive:

• Proof that calibration has been performed according to the quality requirements in ISO 17025 
• Measured uncertainty
• Internationally accepted documentation with the logo of the accreditation body
• Calibration conditions: air temperature, air pressure, and relative humidity

Traceable calibration

Measurements

Calibration of microphones is performed at 250 Hz. Measurements are performed according to IEC 61094 and to the manufacturer’s specifications. All measurements are traceable to institutions such as DPLA, NIST, NPL and PTB.

Certificate

The certificate includes all measurement results.