AP - The Recognized Standard In Audio Test


Calibration Glossary


  • Calibration - the comparison of Instrument performance to a standard of known accuracy.
  • Uncertainty - no measurements can be perfect - uncertainty is expressed as a range of values in which the true value is estimated to lie, within a given statistical confidence. (NPL)
  • Traceability - ability to demonstrate an unbroken chain of comparisons all with stated uncertainties ending with a National Standards Agency - NIST (VIM - International Vocabulary of Basic and General Terms in Metrology)
  • Accreditation - demonstrated compliance with a standard - validated by a recognized third party agency. Acts as a basis for Mutual Recognition Agreements (MRA) with accreditation agencies in other countries.

Calibration FAQ

What is the calibration process?

1. The Customer submits an Order Request form online or via fax. AP and the Customer agree on a date to ship the unit to the factory and pricing is confirmed.
2. When the unit arrives, AP evaluates the unit to determine it is operational and runs a Self Check. If the unit passes the Self Check, it is Calibrated by comparison to our Lab's accredited equipment and a Calibration Report is generated. If service is needed to bring the instrument back to specification, that work is performed.
3. When the unit meets all published specifications, a Calibration Certificate is issued and the unit is returned to the Customer along with the Report and Certificate.

How much does the calibration cost?

Calibration prices vary depending on the instrument and warranty status. Please contact Audio Precision Service for a quote.

What is an Accredited Calibration ?

The Lab has been audited by a recognized third party Accrediting agency to verify the lab meets operational and technical requirements. Audio Precision Calibration Services has been accredited under ISO 17025 by the American Association for Laboratory Accreditation - A2LA. A2LA is Full Member of the International Laboratory Accreditation Cooperation - ILAC, which serves as the world's principal international forum for the development of laboratory accreditation practices and the recognition of competent test facilities worldwide.  In the past some calibration customers have assumed that they could only obtain calibration services from providers that were registered under ISO 9001. This perception was based on the false premise that only ISO 9001 registered calibration providers operate under a recognized quality management system. ILAC in conjunction with ISO and IAF have issued a joint communiqué clarifying that calibration providers that are accredited under ISO 17025 do in fact meet the recognized quality management systems requirements under ISO 9001:2008.  For further details and information see the joint communiqué at http://www.a2la.org/general/ILAC-IAF_Communique.pdf

Which instruments have calibration service available ?

All current models* of analyzers plus System Two can be calibrated. Support for DCX-127, AUX-0025, AUX-0100 and other accessories is not currently available. System One is not supported.
* Portable One requires GPIB. If you have a P1 with a serial number lower than 40,000 please contact Service for availability)

How long does the calibration take?

The estimated time for Accredited Calibration of all instruments is two weeks from the date of the arrival of the instrument. Audio Precision does offer a one week Expedited Service for an additional charge.

I just ordered a new instrument. Do I have to pay extra for the calibration?

An Accredited Calibration is included with all new instruments.

How often should I calibrate my instrument?

Audio Precision recommends that instruments be calibrated once a year.

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