Noise Level Perimeter Survey

Air Quality follows ASTM 1014-12 and similar noise reference methods for stationary boundary noise measurements.

At each monitoring location, a Class-2 or higher noise meter is mounted on a tripod stand with the instrument microphone set at 1.5 meters’ height from the ground level, at least 1.5 meters from the perimeter fence and more than 3.5 meters from any reflecting structure other than the ground (e.g. walls, buildings and other reflecting surfaces).

Air Quality also deploys a portable meteorological station to determine the wind direction, wind speed, temperature and humidity during the noise monitoring.

Some of the primary factors that will figure into the monitoring are: The weather and other site considerations such as rain, wind induced pseudo-noise other local noise;

• The location and direction of any noise source(s).
• The Sound Level Meter (SLM) shall be installed in flat terrain having no excessive sound absorption characteristics such as thick, matted or tall grasses, shrubs, or wooded areas. No obstructions significantly influencing the sound field from the noise source shall exist such as berms or retaining walls that block the line of sight to/from the SLM.
• Avoid reflecting surfaces close to the monitoring location if present. Locate the SLM at least 1-2 meters from any standing structures.
• Always use a windscreen for the microphone. The windscreen can provide protection from wind induced pseudo-noise when there is significant air movement (up to 8.9 m/s).

Air Quality uses Sound Level Meter with weather protection kit and wind shielded microphone for the noise monitoring.  This instrument exceeds all best-practice specifications for noise monitoring by the RCJY, European and US agencies.