Q-2, r. 48 - Regulation respecting hot mix asphalt plants

Schedule Disposition versions

2012-09-01

SCHEDULE B

(s. 11)

METHOD FOR NOISE MEASUREMENT

The noise level at a hot mix asphalt plant is measured according to the following formula:

where

S = 5 where there are 1 or several predominant frequency bands;

S = 0 where there is no predominant frequency band;

I = 5 where there are 1 or several information-bearing noises;

I = 0 where there is no information-bearing noise;

A = A1 + (A2 - A3) calculated as follows:

A1 = attenuation caused by distance;

d2

A1 = 20 log10 ___;

d1

and

d1 = distance from the hot mix asphalt plant to using the following formula;

d2 = distance from the hot mix asphalt plant to the evaluation point;

A2 = attenuation at the evaluation point caused by a barrier;

A3 = attenuation at the measuring point caused by the same barrier;

LI = equivalent level of impact noise.

Calculation of the arithmetic mean of the maximum energies, during the period of emission of the impact noises produced during the sampling period that are recorded at the point of measurement.

The formula to be used is the following:

where

dBn = maximum noise of the Nth impact noise during its emission period.

m = total number of impacts during the emission period; if the number of impacts is over 720/hour, m equals 720.

Lx = equivalent level of a noise.

Equivalent level of a noise at the point of measurement during its period of emission during a sampling period.

The formula to be used is the following:

where fi = time interval (expressed in a percentage of the sampling period) during which the noise level is less than the limit of class i.

Where the hot mix asphalt plant is not in its period of emission, the corresponding fi is equal to 0.

Li = sound level in dBA corresponding to the average of class i.

The scope of class i must be set at a value equal to or less than 2 dBA and the sampling period must be equal to or less than 0.1 seconds.

For the purposes of this measurement method, the normal sampling period is 60 consecutive minutes. If the sampling lasts less than 60 minutes, an adjustment must be made so that the ratio between the periods of emission and the pause are the same.

All the measurements are made in dBA using the rapid response of the sound level meter. The sound level meter and the octave band filters must comply with the standards prescribed in publications 179 (2nd edition, 1973) and 225 (1st edition, 1966) published by Central Office of the International Electrotechnical Commission.

In this measurement method, the hot mix asphalt plant is considered as including the loading, unloading and discharge areas of aggregate material.

R.R.Q., 1981, c. Q-2, r. 25, Sch. B.