Overview
ISO 16063-12:2002 - Methods for the calibration of vibration and shock transducers - Part 12: Primary vibration calibration by the reciprocity method specifies instrumentation and procedures for primary calibration of accelerometers using the reciprocity method and the SI system. The standard covers rectilinear accelerometers over a frequency range of 40 Hz to 5 kHz and a frequency-dependent acceleration amplitude range of 10 m/s² to 100 m/s². Calibration is based on using the coil of an electrodynamic vibrator as the reciprocal transducer and assumes the accelerometer is calibrated together with its signal conditioner or amplifier.
Key Topics and Requirements
- Reciprocity method principle: Uses three transducers (sensor, source, reciprocal transducer) to obtain absolute sensitivity via electromechanical reciprocity; the coil of an electrodynamic vibrator typically serves as the reciprocal element.
- Frequency & amplitude: Preferred amplitudes 10, 20, 50, 100 m/s² and preferred frequencies from ISO 266 one‑third‑octave series; reference frequency 160 Hz.
- Uncertainty targets:
- At 160 Hz and reference amplitudes (100, 50, 20, 10 m/s²): ±0.5% magnitude and ±1° phase.
- Over full range: ±1% magnitude and ±2° phase.
- Annex A provides the uncertainty calculation method.
- Apparatus and performance:
- Frequency generator stability: max uncertainty 0.01%.
- Instrumentation for complex voltage ratio: magnitude uncertainty 0.1%, phase 0.1°.
- Standard resistor uncertainty: 0.05%.
- Test masses: at least five intervals, mass uncertainty 0.05%; largest mass ≈ 0.5–1× moving element mass.
- Power amplifier/vibrator: total harmonic distortion ≤ 2%; signal-to-noise ratio at accelerometer output ≥ 30 dB.
- Seismic block: mass ≥ 2000× moving element mass; vibration isolation recommended.
- Environment: Room temperature (23 ± 3) °C, relative humidity ≤ 75%.
- Documentation: Annex B discusses reciprocity theory; users must produce uncertainty budgets per ISO 16063‑1.
Applications and Users
- Primary reference calibration in national and industrial metrology laboratories and accredited calibration houses.
- Manufacturers of accelerometers and vibration transducers who require traceable sensitivity calibration.
- Test laboratories performing high-accuracy vibration testing, product qualification, and instrumentation verification.
- Useful for establishing traceability chains for vibration measurement and ensuring compliance with high-precision testing requirements.
Related Standards
- ISO 16063‑1: Basic concepts for vibration/shock transducer calibration.
- ISO 16063‑11 & ISO 16063‑13: Primary calibrations by laser interferometry.
- ISO 16063‑21 / ‑22: Comparison and secondary shock calibration methods.
- ISO 266: Preferred frequencies (referenced for frequency selection).
Keywords: ISO 16063-12:2002, primary vibration calibration, reciprocity method, accelerometer calibration, electrodynamic vibrator, SI units, calibration uncertainty, vibration metrology.