1. When it is required to reduce the influence of the surrounding reflection, it should be measured at least 3.5m away from any reflector (except the ground) as far as possible, and the height above the ground should be more than 1.2m, and it should be placed on a high-rise building if necessary and possible. , in order to expand the geographical scope that can be monitored. However, its position and height remain unchanged every time it is measured. Using monitoring vehicle measurements, the microphone is preferably fixed on the roof.
2. Outdoor measurements near buildings, these measurement points should be taken outside the building exposed to the noise environment to be tested. . Unless otherwise specified, the measurement location is preferably 1-2m away from the outer wall, or 0.5m in front of the fully opened windows (including high floors).
3. Measurements in buildings, these measurements shall be carried out in buildings in the environment affected by the noise to be tested. The measurement position is preferably at least 1m away from the wall or other reflective surface, 1.2-1.5m away from the ground, and 1.5m away from the window.
