Overview
ISO 6396:2008 specifies a repeatable laboratory-style method to determine the emission sound pressure level at the operator's position for earth-moving machinery under dynamic test conditions. The standard defines how to measure the time‑averaged A‑weighted emission sound pressure level (LpA,T) while the machine performs simulated dynamic operations. It is intended for machines defined in ISO 6165 and references complementary acoustics and operator-dimension standards.
Key topics and technical requirements
- Measurement quantity: Time‑averaged A‑weighted sound pressure level at the operator’s ear position during dynamic test conditions.
- Instrumentation: Preferably an integrating‑averaging sound level meter complying with IEC 61672-1 (Class 1); calibrated acoustic calibrator required.
- Operator setup:
- Ride-on and pedestrian operator postures specified; operator stature referenced to ISO 3411 (standing stature 1 715 mm ± 50 mm for pedestrian machines).
- Seat adjustments and clothing restrictions to avoid measurement bias.
- Microphone placement & mounting:
- Preliminary check positions: 200 mm ± 20 mm from the head median plane in line with the eyes; choose side giving higher reading.
- Orientation horizontal, pointing where operator would normally look; mounting on helmet, frame or shoulder harness with vibration isolation and minimum clearances to avoid reflections.
- Machine operation:
- Tests use simulated dynamic modes (travel, stationary work cycle, or combined) as defined in ISO 6395:2008 (Annexes B–L).
- Cab tests: doors/windows closed with air-conditioning/ventilation set per clause; if no HVAC, measure closed and open and report the higher value.
- Measurement procedure & result determination:
- At least three measurements per mode; if two values within 1 dB, stop.
- Report the arithmetic mean of the two highest values that are within 1 dB.
- Recordkeeping & reporting: Detailed machine, environmental, instrumentation and acoustical data required; declaration of measurement uncertainty per Annex A.
Applications and users
ISO 6396:2008 is used for:
- Manufacturers for design validation, product documentation and noise reduction.
- Independent test laboratories and acoustical consultants performing operator noise assessments.
- Regulatory bodies and certification agencies assessing compliance with operator-noise limits.
- Health & safety professionals evaluating operator exposure and controlling workplace noise.
Practical uses include comparing machine models, guiding cab and enclosure design, and supporting noise-control measures.
Related standards
Keywords: ISO 6396:2008, earth-moving machinery, operator's position, emission sound pressure level, A-weighted, dynamic test conditions, noise measurement, sound level meter.