Overview
ISO 16063-13:2001 specifies a primary method for shock calibration of rectilinear accelerometers using laser interferometry to measure the time‑dependent displacement of a transducer mounting surface. The standard is part of the ISO 16063 series on methods for calibrating vibration and shock transducers and defines instrumentation, test procedures, data acquisition and processing, and uncertainty reporting for shock sensitivity and complex sensitivity calculations.
Key Topics and Requirements
- Measurement principle: absolute time‑history measurement of displacement by a modified Michelson interferometer (quadrature outputs), with laser displacement converted to acceleration for shock sensitivity.
- Applicable pulses: designed for shock pulse durations in the range 0.05 ms to 10 ms; peak acceleration ranges are pulse‑dependent (the standard provides guidance for practical limits and testing).
- Uncertainty targets:
- Reference condition: expanded uncertainty of 1 % of reading at a reference peak acceleration (document reference: 1 000 m/s²) and 2 ms pulse duration.
- General use: uncertainty specified to be within a larger limit (document indicates up to about 6 % for other pulse/duration conditions); users must prepare an uncertainty budget (Annex A).
- Apparatus requirements:
- Two types of shock machines: rigid‑body (anvil/hammer) and wave‑propagation (long thin bar) designs.
- Seismic block(s) to isolate interferometer and exciter from ground motion.
- Helium–neon laser (or single‑frequency alternative) with known wavelength (0.63281 µm for He–Ne at standard lab conditions).
- Surface and mounting tolerances: surface roughness **Ra