A booth that met specification when installed may not now. Door seals compress, hinges sag, ventilation silencers clog, and the building around the booth changes - a new air handler, a relocated compressor, a busier corridor. None of it is…
A booth that met specification when installed may not now. Door seals compress, hinges sag, ventilation silencers clog, and the building around the booth changes - a new air handler, a relocated compressor, a busier corridor. None of it is visible, and every audiogram taken in a booth that no longer meets ambient limits is affected.
The limits are specified per octave band, because a booth can have a perfectly respectable overall level while failing badly at the low frequencies where building services intrude. An overall A-weighted figure will hide that. We measure and report band by band.
Door seal compression is the most common finding by a wide margin. After that: ventilation paths transmitting corridor noise, cable entry points never resealed after equipment changes, and the booth sitting on a floor that carries structural vibration from plant elsewhere in the building. Most are inexpensive to fix once identified.
Sometimes the booth is fine and the room it sits in is not. Moving the booth, rescheduling testing away from plant operating hours, or treating the surrounding space can all be cheaper than replacing a booth that was never at fault. We will say which it is rather than quoting for a new booth by default.
Primary regulations and standards referenced above. Where a standard is published commercially it is named in full rather than linked to a copy.