ISO 12384:2010

Overview

ISO 12384:2010 - Aerospace - Requirements for digital equipment for measurements of aircraft electrical power characteristics - defines requirements for digital measuring methods and digital measuring equipment used to measure electrical power characteristics on aircraft. The standard targets laboratory and rig testing of aircraft power supply, power distribution and on‑board utilization equipment. It covers accuracy, measurement algorithms, sampling and instrumentation performance for steady‑state and transient conditions.

Key topics and technical requirements

• Measurement scope: constant‑frequency (CF) a.c., variable‑frequency (VF) a.c., and d.c. systems (notably 28 V or 42 V aircraft systems); includes voltage, current, frequency, phase, harmonics, distortion, power factor, voltage spikes and power transfer characteristics.
• Measurement states: clear distinction between steady‑state and transient measurements; transient tests should exercise the whole transient procedure (load switching, source switching, start/stop, etc.).
• Accuracy / admissible errors (examples):
  • Steady‑state a.c./d.c. voltage: ±0.5% absolute error
  • Steady‑state a.c. current: ±1%; d.c. current: ±0.8%
  • a.c. frequency: ±0.1% of nominal
  • Phase difference: ±0.2° (for 110°–130° conditions)
  • Transient voltage/current errors typically larger (e.g., ±1% for transient voltages, ±2% for transient currents)
  • d.c. component errors of a.c. waveforms: up to ±10%
• Sampling and signal processing: sampling requirements for phase voltage measurements (e.g., sampling frequency on each phase not less than 72 kHz; simultaneous three‑phase sampling; sampling time at least one second). Use of digital algorithms and Fourier analysis for modulation and harmonic content is specified.
• Equipment performance & design: accuracy, measurement resolution, input impedance, sampling frequency range, electromagnetic compatibility (EMC), human‑machine interface, software/data processing controls and selection rules.
• Normative references: ISO 1540 (characteristics of aircraft electrical systems) and ISO 7137 (environmental conditions/test procedures).

Practical applications and who uses ISO 12384:2010

• Aerospace test laboratories and bench/rig test facilities performing power system validation and troubleshooting.
• Aircraft electrical systems engineers validating design compliance for CF, VF and d.c. power systems.
• Test equipment manufacturers designing digital measurement instruments for aircraft power characteristics.
• Procurement/specification authors and certification authorities specifying measurement accuracy, sampling and processing requirements for acceptance testing.
• Integration and maintenance teams diagnosing power quality, transients, harmonics and voltage imbalance on aircraft platforms.

Related standards

• ISO 1540 - Aerospace - Characteristics of aircraft electrical systems (normative reference)
• ISO 7137 - Aircraft - Environmental conditions and test procedures for airborne equipment

Keywords: ISO 12384:2010, aircraft electrical power characteristics, digital measuring equipment, aerospace testing, sampling frequency, transient measurement, steady‑state measurement, power system measurement, test laboratory.