ISO 376: standardisation of metallic materials

The calibration standard ISO 376, also available under the European denomination EN ISO 376, has been developed within the scope of the normalisation of metallic materials, and is entitled: "Calibration of force measurement instruments used for the verification of uniaxial testing machines".

This standard covers the calibration of standard force measurement instruments used for the static verification of uniaxial testing machines, such as tension/compression testing machines, and describes classifying procedures for the instruments.

It replaces the previous standard EN 10002-3 dated 1994. In the US, a similar standard was issued under the reference ASTM E74.

ISO 376: precision criteria

Besides the calibration process itself, this standard classifies these instruments according to precision criteria. Such criteria are established on the basis of metrological characteristics registered during calibration, for which admissible maximum values are defined. The same procedure has been adopted for the inaccuracy of calibration forces.

  • ISO 376 class 00

    This is the best. It is reserved for measurement standards of the highest metrological class and can be considered as equivalent to a global measurement inaccuracy of between 0.02% and 0.05%.

  • ISO 376 class 0.5

    Class 0.5 applies to dynamometers used for calibrating the best precision testing machines. Its global measurement inaccuracy class is between 0.1% and 0.25%.

  • ISO 376 classes 1 and 2

    These classes are reserved for dynamometers used to verify ordinary or field testing machines.

    This approach comes from a long-established practice used before the current concept of measurement inaccuracy was implemented. A draft appendix on calculating calibration inaccuracy has been developed and should be incorporated during the next revision of the standard.

    ISO 376 is the only standard at the international level which covers dynamometer calibration. Its original scope has been extended to cover several other aspects, such as non-metallic materials, hard materials, concretes, etc.

National standards prior to ISO 376

With a few exceptions, previous national standards such as:

    • DIN 51301
    • NBN X 07-011
    • NFA A 03-510
    • QPMAM / M / B / 070

have been replaced by a unified EN ISO 376.

NOTE : Spanish version /en/tecnologia/normas/iso-376-para-la-calibracion-de-transductores-de-fuerza