Verification or Calibration?



In general usage, the term “verification” is often mixed up with “calibration”.

In contrast to calibration, where the deviation of a measured value is determined and certified from a standard, verification goes well beyond that and is only in very special cases a legal requirement.

For a number of measuring instruments, a state-driven legal requirement for verification exists.

That means that they may only be used if they have been verified by a nationally recognised testing laboratory.

Verification is therefore the state-required testing of measuring instruments.

In doing this, based on a consistency quality test, it is determined whether the measuring instruments are able to be verified.

In the subsequent metrological testing it is checked whether the measuring instrument complies with the specified maximum permissible errors and conforms to other requirements that are defined in the verification ordinance or in the EU directives.

Included in this category are such as water meters, commercial scales, petrol pumps, radar measuring instruments or measuring equipment for automotive exhaust gases.

In addition, pressure gauges must therefore 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.

Overview of the differences between verfication and calibration:

Verification
Verification – Only when it is a legal requirement (not ISO9000):

- Determining compliance with legally prescribed verification error limits

- Officially recognised and legally binding verification testing

- Verification certification or conformity certificate (“initial verification”)

Calibration
DKD calibration – Specifically if metrological traceability is necessary:

- Per calibration point, the deviation and measurement uncertainty is determined and documented in the calibration certificate

- Trusted measuring results with traceability to international standards - DKD calibration certificate

Tel: 01737 644 008
Email: info@wika.co.uk
Web: www.wika.co.uk

Published in Valve User Magazine Issue 50


Autumn 2019 // Issue 50
Read latest articles Pageflip Magazine Version Download Magazine