DAkkS calibration – the right path to a calibration certificate

Calibration by WIKA

Since 1982 WIKA has been a member of the German Calibration Service (Deutscher Kalibrierdienst - DKD) - the calibration laboratory and the mobile calibration service have been accredited by the German accreditation body (Deutsche Akkreditierungsstelle - DAkkS) to DIN EN ISO / IEC 17025. Thus, with WIKA, you can be sure that an ISO calibration and the generation of a calibration certificate is always carried out in compliance with legal and normative requirements and also on an internationally comparable level.

What is a DAkkS calibration?

In measurement technology, calibration means determining the measuring deviation of the respective measuring instrument. In contrast to adjustment, in calibration there is no intervention with the measuring instrument. If an indicating measuring instrument is calibrated, the measuring deviation between the measured value indication and the actual value is recorded. For material measures, for example masses, the difference is determined between the marking and the actual value. For measuring chains, the measuring deviation between the value of the output signal and the value that the signal should have with an ideal transfer characteristic and a given input value is determined.

In the DIN EN ISO 9000 and the DIN EN ISO / IEC 17025 family of standards, traceability to national standards is required for a DAkkS calibration. With traceability, the measured value indication (or a material measure) is compared with the respective standard for the measurand.

The National Metrology Institute of Germany (Physikalisch-Technische Bundesanstalt - PTB) is the highest technical authority in Germany for metrology. The PTB maintains and develops the national standards. It ensures the international comparability through cooperation with other national institutes.

Through a DAkkS calibration of measuring and test equipment and the traceability of measurements to national standards, reliable acquisition of process variables is ensured. An ISO calibration by WIKA thus contributes directly to safeguarding your product quality.

What is a DAkkS calibration certificate?

The WIKA calibration laboratories check your measuring instruments in the form of a factory calibration or a traceable calibration in accordance with ISO 17025. The result of the ISO calibration is recorded in a calibration certificate. Through the European co-operation for Accreditation (EA) it is ensured that your calibration certificate will also be recognised in other countries. We generate calibration certificates for the measurands pressure, temperature, DC current, DC voltage and DC resistance.

We would be happy to issue a calibration certificate for your measuring instruments too. Please use our form for (re)calibrations.

What is the difference between a DAkkS calibration and a factory calibration?

The significant difference between the two calibrations is that only ISO 17025 calibration guarantees traceability to the national standard. In accordance with the ranking order of the standards – from the working or factory standard through the reference standard to the national standard – there is a calibration hierarchy. Sources of error such as hysteresis and repeatability are also measured and documented together with the measuring deviation and the uncertainty of the reference, and summarised in the expanded measurement uncertainty. The calibration to ISO 17025 is thus more accurate, more extensive and also internationally recognised in comparison with the factory calibration. DAkkS calibration certificates may only be issued by accredited calibration laboratories, such as the WIKA calibration laboratory. A factory calibration only considers the hysteresis and determines the deviation, which is documented in an inspection certificate in accordance with DIN EN 10204. You can learn more about the differences in the video Factory calibration vs. traceable DAkkS calibration in accordance with ISO 17025.

When is a DAkkS calibration required?

A DAkkS calibration is necessary if

  • it is required by the contracting company
  • the calibration certificate must be internationally recognised
  • reference instruments need to be calibrated

What is the difference between a verification and a calibration?

The terms “Verify” and “Calibrate” are often mixed up. With a calibration, the deviation of the measured value from a standard is determined and certified. Verification, on the other hand, is the state-required testing. Measuring instruments that are subject to compulsory state validation may only be used after this verification.

Pressure gauges, for example, must only be verified if their suitability (for example because of a specific measurement accuracy) serves to protect the health and safety of people or to measure dimensions in the free movement of goods.