ISO 5347-22:1997

Overview

ISO 5347-22:1997 defines general methods for accelerometer resonance testing, a critical process in the calibration of vibration and shock pick-ups. This international standard provides detailed specifications for the instrumentation and procedures used to determine the resonance frequencies of rectilinear accelerometers. These accelerometers include piezoresistive, piezoelectric, and variable capacitance types, operating within the frequency range of 50 Hz to 200 kHz.

Accurate resonance testing ensures that accelerometers used in vibration and shock measurement deliver reliable, stable readings across their operational range. The document supports consistent calibration practices to enhance the performance and safety of equipment relying on vibration analysis.

Key Topics

• Scope and Applicability

  • Focuses on accelerometer resonance testing for three key sensor types: piezoresistive, piezoelectric, and variable capacitance accelerometers.
  • Covers frequency response measurements between 50 Hz to 200 kHz, an essential range for industrial and scientific applications.

• Instrumentation and Apparatus Specifications

  • Defines equipment requirements including frequency generators, power amplifiers, oscilloscopes, and vibrators capable of the specified frequency range.
  • Specifies the use of standardized reference blocks made of steel or beryllium, depending on resonance frequency, to provide reproducible testing conditions.
  • Details required conditions for mounting accelerometers to minimize measurement errors related to surface flatness, roughness, and perpendicularity.

• Testing Procedures

  • Describes mounting procedures based on ISO 5348 for consistent and repeatable accelerometer placement.
  • Outlines methods for measuring mounted resonance frequency using sinusoidal vibrations and comparison against a standard accelerometer.
  • Includes protocols for detecting local resonances and how to interpret phase angle changes near resonance frequencies.
  • Covers cross-axis resonance frequency testing to evaluate accelerometer sensitivity perpendicular to the primary axis.
  • Provides a shock method for determining the damped natural frequency through controlled transient shock pulses, including data acquisition and analysis requirements.

• Data Analysis and Interpretation

  • Guidance on identifying primary and minor resonance peaks.
  • Explains interpretation of phase angle changes, especially the significance of a 180° phase shift near resonance.
  • Criteria for reporting secondary resonance or local resonances when their output is significantly lower than the primary resonance peak.

Applications

• Calibrating Accelerometers in Industrial Monitoring

  • Ensures accelerometer accuracy for condition monitoring in machinery, aerospace, automotive testing, and structural health monitoring.
  • Improves reliability of vibration data critical in predictive maintenance and troubleshooting.

• Quality Control in Sensor Manufacturing

  • Supports manufacturers in confirming accelerometer performance characteristics meet specifications.
  • Facilitates consistent product testing before shipment or installation.

• Research and Development

  • Enables precise characterization of sensor response for new accelerometer designs.
  • Helps validate modeling and simulation results for sensor behavior under variable operating conditions.

• Certification and Compliance

  • Assists calibration laboratories and testing facilities in meeting international standards.
  • Promotes global harmonization of vibration and shock sensor testing methods, supporting cross-border equipment deployment.

Related Standards

• ISO 5348: Mechanical vibration and shock - Mechanical mounting of accelerometers, providing details on mounting techniques crucial to resonance testing accuracy.
• Other parts of the ISO 5347 series cover a comprehensive range of vibration and shock pick-up calibration methods:
  • Part 0: Basic concepts
  • Part 3 & 4: Secondary vibration and shock calibration
  • Part 74: Resonance frequency testing of undamped accelerometers on a steel block
  • Part 79: Testing of magnetic field sensitivity
  • Additional parts addressing specific calibration types and sensitivity tests across frequency, temperature, and mechanical parameters.

Leveraging ISO 5347-22 as part of an integrated calibration strategy helps maintain high-quality vibration measurement systems essential in many technical and safety-critical fields.