Overview
ISO 16900-14:2020 specifies laboratory test methods for measuring the sound pressure level produced by respiratory protective devices (RPDs) and by RPD warning devices. Measurements are made on a standardized headform fitted with special ear inserts and microphones while the RPD is operated under defined breathing-machine or metabolic-simulator conditions. The standard defines two main methods: Method A (noise level of the RPD, excluding warning devices) and Method B (warning sound pressure level).
Key topics and technical requirements
- Test set-up
- Use the ISO RPD headform (medium size) attached to an RPD torso; torso covered with a cotton T‑shirt to avoid reflected noise.
- Microphones mounted in special ear inserts; microphone surface positioned at the flat ear surface ±1 mm.
- The headform is used regardless of the RPD interface size to ensure repeatable acoustical coupling.
- Equipment
- Sound level meter meeting IEC 61672-1 Class 2 (Method A) and a sound spectrum analyser capable of one‑third‑octave bands per IEC 61260-1 (Method B).
- Sound level calibrator meeting IEC 60942 Class 2 and an adaptor for in‑situ calibration.
- Microphones specified as 12 mm diameter pressure or omnidirectional types depending on method.
- Breathing machine or metabolic simulator as per ISO 16900-5.
- Procedures
- Calibrate microphone/system with calibrator before measurement.
- Measure A‑weighted equivalent continuous sound pressure level (Lp,A,eqT) at left and right ears (Method A) or at the ear nearest the warning device (Method B).
- Background noise (with breathing machine running but without RPD) must be measured - maximum 70 dBA.
- Ambient test conditions normally 16 °C to 32 °C and (50 ± 30) % RH.
- Reporting and uncertainty
- Test report must include parameters listed in Clause 4 (number of specimens, conditioning, operating conditions, duration, deviations), background level, maximum measured Lp,A,eqT and an estimate of measurement uncertainty (see Annex A and guidance such as JCGM 100).
Applications and users
- Who uses it:
- RPD manufacturers (design validation and product development)
- Accredited testing laboratories and certification bodies
- PPE safety engineers, acousticians, and regulatory compliance teams
- Practical uses:
- Quantifying wearer noise exposure and comfort
- Verifying audibility and compliance of integrated warning devices
- Supporting performance standards, product labeling, and certification
Related standards
Keywords: ISO 16900-14, respiratory protective devices, sound pressure level, RPD noise measurement, A‑weighted sound level, RPD warning devices, headform testing.
Open preview (PDF)Respiratory protective devices — Methods of test and test equipment — Part 14: Measurement of sound pressure level
