ISO 16902-1:2003

Overview

ISO 16902-1:2003 - Hydraulic fluid power - Test code for the determination of sound power levels of pumps using sound intensity techniques (engineering method, Part 1: Pumps) provides a practical test code for measuring airborne noise from hydraulic pumps under controlled installation and operating conditions. Based on ISO 9614‑1 and ISO 9614‑2 (with reference to ISO 9614‑3), the standard is intended for comparing noise emissions of pumps that convert rotary mechanical power into hydraulic fluid power, including devices fitted in normal service (valves, solenoids, gears, couplings, etc.). The measured sound power includes radiation from any piping enclosed by the measurement surface.

Key topics and requirements

• Measurement method: Sound intensity measurements in octave and one‑third‑octave bands using ISO 9614 series methods; narrow‑band measurements are permitted because pump noise is dominated by pumping‑frequency harmonics.
• Measurement surfaces: Surfaces must follow ISO 9614 guidance; piping should ideally not pass through surfaces (split surfaces if necessary); shielding of external piping allowed if ≤10% of surface area.
• Reflecting planes: Guidance on size (see ISO 3744 Annex A); reflecting planes should be uncoupled from pump with soft rubber seals and be rigid (concrete/brick suitable); nearby large reflective surfaces should be ≥2 m away unless used as reflecting plane.
• Installation & mounting: Pump mounting should minimise radiated noise (passive damping recommended); drive coupling must follow manufacturer recommendations; drive motor and couplings should be outside the measurement surface.
• Hydraulic circuit & test fluid: Include the filters, coolers, reservoirs and valves needed to reproduce operating conditions; test fluid, temperature and contamination levels per manufacturer recommendations; inlet/discharge piping sized per manufacturer guidance.
• Operating tolerances: Maintain flow, pressure and speed within ±2% and temperature within ±2 °C during tests.
• Documentation: Record measurement uncertainty, test conditions, pump details and produce a test report per the standard.

Applications and users

ISO 16902-1 is used by:

• Acoustic test laboratories and certification bodies
• Hydraulic pump manufacturers and R&D teams
• OEMs and system integrators selecting pumps for noise‑sensitive equipment
• Engineers performing product comparisons, noise control, and design validation

Practical uses include component selection, comparative product data, design improvements for quieter pumps, and supporting procurement and regulatory decisions related to machine noise.

Related standards

• ISO 9614‑1, ISO 9614‑2, ISO 9614‑3 (sound intensity measurement)
• ISO 3744 (sound power in an essentially free field over a reflecting plane)
• ISO 4412‑1 (reference method mentioned)
• ISO 5598 (fluid power vocabulary)
• IEC 61043 (instruments for sound intensity)
• ISO 3448, ISO 6743‑4 (lubricant classifications)

Keywords: ISO 16902-1, hydraulic fluid power, sound power levels, sound intensity techniques, pump noise testing, acoustic measurement, measurement surfaces, reflecting plane.