ISO 19924:2017

Overview

ISO 19924:2017 - Space systems - Acoustic testing provides guidance for implementing acoustic tests of spacecraft, subsystems, modules and units. Intended as a supplement to ISO 15864, it defines a framework for acoustic test systems, technical requirements and procedures for tests performed in reverberant chambers. The standard also describes criteria for manual test interruption, handling and evaluation, and allows tailoring of technical requirements to meet specific test objectives.

Key topics and technical requirements

• Test purpose: Demonstrate specimen endurance to launch acoustic environments and validate random vibration levels; detect workmanship and material defects; support design qualification with margin.
• Test systems: Composition and requirements for a reverberant test facility - chamber system, gas supply, sound source, control and measurement systems.
• Chamber requirements: Polyhedral, rigid, reflective surfaces; sufficient volume (recommended ≥ 10× specimen volume where possible) to achieve low-frequency homogeneity; OASPL capability above test requirements.
• Acoustic field types: Broadband reverberant field (typical 22.5 Hz–10 000 Hz, 1/3-octave) and provisions for direct field acoustic tests (DFAT) when RFAT is not feasible.
• Instrumentation & control: Control points, multipoint control (average of control signals), closed-loop and open-loop control options, measurement points, sound pressure level (SPL) and OASPL measurement methods.
• Test technical details: Laboratory environment, test conditions and tolerances, fill effect (payload influence on chamber response), specimen configuration/installation, accelerometer usage for structure response, safety requirements.
• Procedure & data: Pre-test checks, implementation steps, post-test actions, manual test interruption criteria, interruption handling, data capture and result evaluation, and documentation.
• Definitions & metrics: Terms such as SPL, OASPL, RMS, PSD, octave and third-octave bands, statistical degrees of freedom.

Applications and who uses it

ISO 19924 is used by:

• Aerospace test providers and reverberant chamber facilities
• Spacecraft manufacturers, payload and subsystem integrators
• Acoustic and structural engineers validating launch survivability
• Test planners and qualification engineers preparing test procedures and acceptance criteria Practical applications include launch acoustic qualification, compatibility testing, verification of acoustic environments for payloads, and correlating acoustic to random vibration test levels.

Related standards

• ISO 15864:2004 - Space systems - General test methods for spacecraft, subsystems and units (supplemented by ISO 19924)
• ISO 14620 - Space systems - Safety requirements
• ISO 266 - Preferred centre frequencies of octave and third-octave bands (referenced for band definitions)

Keywords: ISO 19924, acoustic testing, space systems, reverberant chamber, sound pressure level, OASPL, acoustic reverberation, payload fill effect, RFAT, DFAT.