TRACEABILITY, REFERENCE MATERIALS AND STANDARDISED TESTS IN OPTICAL STRAIN MEASUREMENT

Imaging methods are applied in engineering and experimental mechanics areas to measure strain fields. The SPOTS project tackles the problem of traceability in optical strain measurement. Strain, being a displacement derivative, is a measurement quantity derived from the base unit length. We outline routes for traceability of optical strain measurement values, and underline the role of measurement standards for strain. Measurement uncertainty for calibration of an ESPI interferometer is detailed.