PERFORMANCE STANDARDS FOR ALL USES.
Frequency Band (Cycles per second) | Maximum Permitted Sound-Pressure Level (Decibels) |
|---|---|
20-75 | 69 |
75-150 | 54 |
150-300 | 47 |
300-600 | 41 |
600-1,200 | 37 |
1,200-2,400 | 34 |
2,400-2,800 | 31 |
Above 4,800 | 28 |
If the noise is not smooth and continuous (if the variation of the noise level involves maximum at intervals of one second or less, it is to be considered as continuous noise) or it is not radiated at nighttime, one or more of the corrections below shall be added to or subtracted from each of the decibel levels given above. |
Type of Operation of Character of Noise | Correction in Decibels. |
|---|---|
Daytime operation only (7:00 a.m. to 10:00 p.m.) | +5 |
Noise occurs less than 5% of any one-hour period | + 5 |
Noise is of peculiar character (hum, scream, etc.) or is of impulsive character (hammering, etc.) (In the case of impulsive noise, the correction shall apply only to average pressure during an impulse, and impulse peaks shall not exceed the basic standards given above). | -5 |
PERFORMANCE STANDARDS FOR ALL USES.
Frequency Band (Cycles per second) | Maximum Permitted Sound-Pressure Level (Decibels) |
|---|---|
20-75 | 69 |
75-150 | 54 |
150-300 | 47 |
300-600 | 41 |
600-1,200 | 37 |
1,200-2,400 | 34 |
2,400-2,800 | 31 |
Above 4,800 | 28 |
If the noise is not smooth and continuous (if the variation of the noise level involves maximum at intervals of one second or less, it is to be considered as continuous noise) or it is not radiated at nighttime, one or more of the corrections below shall be added to or subtracted from each of the decibel levels given above. |
Type of Operation of Character of Noise | Correction in Decibels. |
|---|---|
Daytime operation only (7:00 a.m. to 10:00 p.m.) | +5 |
Noise occurs less than 5% of any one-hour period | + 5 |
Noise is of peculiar character (hum, scream, etc.) or is of impulsive character (hammering, etc.) (In the case of impulsive noise, the correction shall apply only to average pressure during an impulse, and impulse peaks shall not exceed the basic standards given above). | -5 |