ISO 5347-8:1993

Overview

ISO 5347-8:1993 is an international standard developed by the International Organization for Standardization (ISO) that specifies the primary calibration method for vibration and shock pick-ups using a dual centrifuge. This method is crucial for ensuring the accurate measurement of accelerations by accelerometers, which are widely used in mechanical vibrations and shock testing. The standard applies to all types of rectilinear accelerometers, including primary standards and working instruments, within a frequency range of 0.7 Hz to 10 Hz and a dynamic acceleration range from 10 m/s² to 100 m/s². It mandates calibration uncertainties to remain within ±2% of the reading.

This standard complements other parts of ISO 5347, which covers various calibration techniques and sensitivity tests for vibration and shock sensors.

Key Topics

• Dual centrifuge calibration setup
  Specifies using two rotary tables rotating at controlled frequencies, with one mounted on the other eccentrically and perpendicularly, to create precise acceleration levels for the calibration process.

• Instrument requirements

  • Temperature control equipment maintaining ambient temperature at 23°C ± 3°C
  • Dual rotating tables with accurately measured distance between rotation centers (uncertainty ≤ ±0.1%)
  • Frequency measurement devices with uncertainty under ±0.1%
  • Voltmeter for true RMS output voltage measurement with an uncertainty under ±0.1%

• Calibration procedure
  Covers steps to set rotational speeds of tables, measure sensor output, calculate calibration constants, and apply correction factors for positional errors. Calibration is performed at various frequencies and acceleration amplitudes.

• Uncertainty calculation
  Provides a detailed method to calculate both random and systematic uncertainties in calibration results, expressing the total expanded uncertainty at a 95% confidence level. Includes consideration of environmental factors, instrument stability, and frequency and amplitude linearities.

• Performance parameters

  • Frequency range: 0.7 to 10 Hz
  • Dynamic acceleration: 10 m/s² to 100 m/s²
  • Calibration uncertainty: ±2%
  • Recommended calibration acceleration value: 100 m/s² (preferred) or 50 m/s² (alternative)
  • Reference calibration frequency: 5 Hz (preferred) or 1 Hz (alternative)

Applications

ISO 5347-8:1993 serves a vital role in industries and laboratories that require precision calibration of accelerometers for vibration and shock measurements, including but not limited to:

• Mechanical engineering: Testing and analysis of machinery vibration to prevent failures.
• Automotive and aerospace industries: Calibration of sensors used in vehicle and aircraft testing environments.
• Research labs: Ensuring traceability of accelerometer measurements to primary standards.
• Quality assurance: Compliance with client or regulatory requirements for sensor performance validation.
• Environmental monitoring: Calibration of seismic or structural health monitoring sensors.

By adhering to this standard, laboratories and organizations can ensure traceable, reliable, and precise acceleration measurements, which are critical for safety, product performance, and regulatory compliance.

Related Standards

ISO 5347-8:1993 is part of a comprehensive suite of standards for vibration and shock sensor calibration:

• ISO 5347-0: Basic concepts of vibration and shock calibration.
• ISO 5347-1: Primary vibration calibration using laser interferometry.
• ISO 5347-2: Primary shock calibration by light-cut method.
• ISO 5347-7: Primary calibration by single centrifuge method.
• ISO 5347-9: Secondary vibration calibration by phase-angle comparison.
• Various other parts address sensitivity tests and calibration of shocks at different levels and frequency responses.

These related standards provide complementary methods and testing procedures that expand capabilities beyond the dual centrifuge technique detailed in ISO 5347-8.

Keywords: ISO 5347-8, accelerometer calibration, dual centrifuge, vibration sensor calibration, primary calibration, shock pick-ups, dynamic acceleration, frequency range, calibration uncertainty, vibration testing, shock measurement standards, mechanical vibrations.