ISO 8626:1989

Overview

ISO 8626:1989 - "Servo-hydraulic test equipment for generating vibration - Method of describing characteristics" is an ISO international standard that defines a consistent method for describing and reporting the characteristics of servo‑hydraulic vibration test equipment. Published in 1989 by ISO/TC 108 (Mechanical vibration and shock), it standardizes the list of properties to be reported, the method for obtaining certain parameters, and two levels of description (Level 1 and Level 2) to enable fair comparison and specification of equipment.

Key topics and requirements

• Scope and components covered
  • Applies to hydraulic vibration generators (actuators, pistons, moving elements, position transducers), servovalve control devices, hydraulic power systems and complete hydraulic vibration generator systems.
  • Auxiliary tables and certain control desks are referenced (ISO 6070 covers auxiliary tables).
• Two-level description
  • Level 1: Minimum set of characteristics the manufacturer must publish in product literature.
  • Level 2: More detailed properties to be supplied by agreement between user and manufacturer (used in tenders and technical contracts).
• Standardized characteristic list
  • Includes supply pressure, flow rates, rated travel and velocity, mass of moving element, rated dynamic force (sinusoidal and random/broad-band), modal frequency, hydraulic stiffness, damping, maximum no‑load acceleration, and environmental/installation conditions.
• Measurement and reporting methods
  • Defines the standard method for obtaining certain parameters (see Annex B: methods for measuring or calculating generator parameters).
  • Provides schematic diagrams (Annex A) and guidance on selection of test masses (Annex C).
• Documentation
  • Specifies technical documents manufacturers must supply with equipment (performance data, installation and operating conditions, control and protection details).

Practical applications and users

• Useful for:
  • Test‑lab engineers specifying vibration test systems for product qualification.
  • Procurement teams writing tenders for servo‑hydraulic shakers and complete systems.
  • Manufacturers and system integrators preparing consistent product literature and technical offers.
  • R&D and quality assurance teams comparing equipment performance (rated force, PSD, travel, frequency response).
• Practical benefits:
  • Ensures consistent comparison across different suppliers.
  • Facilitates selection of a hydraulic vibration system matched to test masses, frequency bands and required acceleration PSD.
  • Helps verify installation, environmental and auxiliary equipment requirements before procurement and commissioning.

Related standards

• ISO 2041 (vibration vocabulary)
• ISO 3746 (acoustics survey method)
• ISO 4406 (hydraulic fluid contamination coding)
• ISO 4413 (hydraulic fluid power - general rules)
• ISO 6070 (auxiliary tables for vibration generators)

Keywords: ISO 8626:1989, servo‑hydraulic test equipment, hydraulic vibration generator, servovalve control device, hydraulic power system, vibration test specification, rated force, acceleration PSD, test masses.