Section 20-2903. EQUIPMENT SETTINGS

 

2903.1In measuring impulsive or rapidly fluctuating noise, the following procedures shall be followed:

 

(a)A windscreen shall be used for all outdoor measurements;

 

(b)The "C" scale shall be used on the sound level meter;

 

(c)The attenuator shall be set so that the measured levels fall between the zero mark and the full scale mark on the meter scale; and

 

(d)The fast meter response shall be used on the sound level meter.

 

2903.2In measuring steady (including intermittent, slowly fluctuating, or quasi-steady) noise, the following procedures shall be followed:

 

(a)A windscreen shall be used for all outdoor measurements;

 

(b)The "A" scale shall be used on the sound level meter;

 

(c)The attenuator shall be set so that the measured levels fall between the zero mark and the full scale mark on the meter scale. At least five (5) seconds shall elapse after the attenuator is changed before measurements are taken; and

 

(d)The slow meter response shall be used on the sound level meter.

 

source

Final Rulemaking published at 26 DCR 1499, 1502 (September 28, 1979).