The accuracy of results is dependent on various parameters which may be separated into two categories:
- metrological parameters such as class of machine and extensometer and the accuracy of specimen dimensional measurements;
- material and testing parameters such as nature of material, test piece geometry and preparation, testing rate, temperature, data acquisition and analysis technique.
In the absence of sufficient data on all types of materials it is not possible, at present, to fix values of accuracy for the different properties measured by the tensile test.
Annex J provides a guideline for the determination of uncertainty related to metrological parameters.
Annex K provides values obtained from interlaboratory tests on a group of steels and aluminium alloys.