HelplineIntercomparisons Details
Standards facilities are characterized by meticulous attention to detail in ensuring that the measurement uncertainty is kept to a practical minimum. However it is important to demonstrate that systematic bias has been eliminated and this can only be done by comparing with other facilities of an equal, or higher, metrological standing in round-robin exercises known as intercomparisons. In the case of flow, a package of one or more meters, often within associated pipework to ensure that flow conditions are not affected by mismatched pipes, is passed from laboratory to laboratory and the calibration curves are compared. TUV NEL is involved in intercomparisons at many levels, both as a leader and as a participant.
The highest level of international intercomparison is the key intercomparison in support of the Mutual Recognition Agreement. In these exercises each region, e.g. Europe, the Americas or the Far East, appoints a pivot laboratory with one pivot acting as a world leader, or pilot laboratory. A meter package is designed and built by the pilot and circulated round other pivot laboratories. Each pivot then produces a clone of this package to circulate round the laboratories in its regional group.
Within Europe, TUV NEL is a major player in EUROMET and has taken part in many recent EUROMET intercomparisons in the flow area. TUV NEL has also been involved in other international exercises and details of each are available by clicking on the appropriate box in the diagram below.
As the custodians of the national standards for flow, TUV NEL sits at the pinnacle of the flow calibration hierarchy in the UK. As a result, TUV NEL's facilities are involved as a reference in intercomparisons between other test facilities, these being run under the auspices of UKAS or Trading Standards.