ISO 16063-33:2017

Overview

ISO 16063-33:2017 - Methods for the calibration of vibration and shock transducers - Part 33: Testing of magnetic field sensitivity specifies laboratory procedures and apparatus requirements for measuring how vibration and shock transducers respond to external sinusoidal magnetic fields. The standard applies to all types of vibration/shock transducers and covers reference test fields at 50 Hz or 60 Hz with r.m.s. magnetic flux densities above 10⁻³ T (typically 10⁻² T). It is intended for calibration laboratories, manufacturers and metrology institutes needing internationally consistent magnetic‑sensitivity measurements.

Key topics and requirements

• Test principle: Determine the transducer’s maximum output in a reference magnetic field and express magnetic field sensitivity S as S = X_B,max / B, where X_B,max is the transducer maximum output (r.m.s.) and B is the test magnetic flux density (r.m.s., in tesla).
• Magnetic field sensitivity tester: A dedicated tester uses a pair of coils (two coils) symmetrically mounted with distance D equal to coil radius R (D = R). The test platform is non‑ferromagnetic, rotatable and centred between coils.
• Apparatus specs
  • Coil arrangement: Two coils rotated horizontally; field uniformity within ±3% near centre.
  • Platform: Mass > 50 × transducer mass; allow ≥180° rotation around the transducer’s sensitivity axis.
  • Vibration isolation: Eigenfrequency < 30 Hz to reduce ambient vibration.
  • Electrical equipment: Adjustable AC current at 50/60 Hz; conditioning amplifier (max expanded uncertainty of gain 1%); true r.m.s. voltmeter (1%); r.m.s. teslameter (2%).
• Measurement conditions: Room temperature ~ (23 ± 5) °C, relative humidity ≤ 75%, signal‑to‑noise ratio SNR ≥ 20 dB (if SNR < 20 dB, uncertainty contributions from ambient noise must be included).
• Procedure: Adjust field with teslameter, mount transducer with non‑magnetic stud, rotate coils 360° to find plane maximum, incrementally rotate transducer (e.g. 15° steps) through 180°, record maxima and compute sensitivity. Annexes describe an automatic test system and an alternative three‑orthogonal‑coil method.

Applications and users

• Calibration and metrology laboratories validating the electromagnetic immunity/vulnerability of accelerometers, velocity and displacement transducers.
• Transducer manufacturers performing factory acceptance and type testing.
• Quality assurance and maintenance teams verifying sensor performance in environments with mains magnetic fields (50/60 Hz).
• Research groups assessing transducer behaviour under controlled magnetic fields.

Related standards

• ISO 16063-1:1998 - Methods for the calibration of vibration and shock transducers - Part 1: Basic concepts (referenced normative document).

Keywords: ISO 16063-33:2017, magnetic field sensitivity, vibration transducer calibration, shock transducers, teslameter, true RMS voltmeter, conditioning amplifier, coil tester, magnetic flux density, SNR.