ISO 5347-13:1993

Overview

ISO 5347-13:1993 defines the standardized methods for testing the base strain sensitivity of vibration and shock pick-ups, specifically rectilinear accelerometers, mainly of the piezoelectric type. This standard is a crucial part of the ISO 5347 series, which covers comprehensive calibration and testing procedures for vibration and shock sensors. The document provides detailed specifications for instrumentation, test surfaces, and procedures necessary to accurately assess how base strain affects the sensor output.

The calibration of vibration and shock pick-ups ensures reliable performance in applications where precise measurement of mechanical stress, vibration, and shock is critical. By adhering to ISO 5347-13, manufacturers and testing laboratories can validate sensor sensitivity under well-defined strain conditions, ensuring repeatability and conformity in measurement results worldwide.

Key Topics

• Scope: Applies to rectilinear, primarily piezoelectric accelerometers; focuses on base strain sensitivity testing.
• Test Parameters:
  • Reference values: base radius of curvature 25 m, base strain 2.5×10^-4
  • Check values include radius of curvature 62.5 m with strain 1×10^-4, and radius 12.5 m with strain 5×10^-4
• Test Surfaces: The sensor mounting surface must be flat and polished to an arithmetic roughness (Ra) below 1 micron, with strict tolerances on drilled hole perpendicularity and mounting geometry.
• Test Fixture: A steel cantilever beam fixed at one end provides the required curvature and strain levels; the test location is precisely defined for consistent strain application.
• Instrumentation: Use of strain gauges (extensometers), force measurement devices, and low-frequency amplifiers to monitor applied strain and sensor output.
• Test Procedure:
  • Apply a known force incrementally to induce base strain in multiple directions around the sensor.
  • Measure sensor output and strain simultaneously to determine base strain sensitivity.
  • Repeat measurements in four directions to verify sensor performance uniformly.
• Calculation: Sensitivity is calculated as the ratio of sensor output acceleration signal to applied strain, ensuring results conform to defined uncertainty limits.

Applications

ISO 5347-13 is essential for:

• Sensor Manufacturing: Ensuring that accelerometers meet quality standards for strain sensitivity, enhancing product reliability.
• Calibration Laboratories: Providing a reproducible method to verify sensor characteristics, vital for traceability to international standards.
• Research & Development: Studying how mechanical base strain influences sensor accuracy, aiding in the design of more robust accelerometers.
• Industrial Testing and Monitoring: Validating sensors used in environments where mechanical strain or base distortion might impact accurate vibration or shock measurements, such as aerospace, automotive, and structural health monitoring.
• Quality Assurance: Assisting organizations in maintaining compliance with international measurement standards, thereby supporting global equipment interoperability.

Related Standards

ISO 5347-13 is part of the broader ISO 5347 series on vibration and shock pick-up calibration, including but not limited to:

• ISO 5347-0: Basic concepts for vibration and shock sensor calibration.
• ISO 5347-1 & -2: Primary calibration methods using laser interferometry and light cutting techniques.
• ISO 5347-11 & -12: Sensitivity testing for transverse vibrations and shocks.
• ISO 5347-14: Resonance frequency testing on non-damped accelerometer masses.
• ISO 5347-15 to -19: Tests related to acoustic sensitivity, temperature, torque, and magnetic field influences.

These complementary standards provide complete guidance on calibration techniques and environmental sensitivity tests, ensuring comprehensive assessment of vibration and shock sensors for various use cases.

Keywords: ISO 5347-13, base strain sensitivity, vibration pick-up calibration, piezoelectric accelerometer testing, shock sensor calibration, accelerometer base strain test, mechanical strain effects, sensor standardization, vibration measurement calibration, ISO vibration standards.