In ÖNORM EN ISO 14577-4 a method for testing layers is specified, which is particularly applicable to testing thin layers in the nano and micro range. This test method is limited to testing individual layers if the indentation is perpendicular to the surface of the sample to be tested. However, gradient layers and multiple layers in cross section can also be measured if the thickness of the individual layers or the width of the gradation is greater than the spatial resolution of the penetration process. The test method is not limited to any type of material. Metallic, non-metallic and organic layers are included in the scope of this standard. The application of this standard with regard to hardness measurement is only possible, when the indenter is a pyramid or a cone with a tip radius small enough for plastic deformation to occur in the layer. The hardness of viscoelastic materials or materials that exhibit significant creep is significantly affected by the time it takes to perform the test.
