LOCAL - NATIONAL - INTERNATIONAL
RISK ASSESSMENTS, HAZOP - FMEA- ETA- HRA STUDIES, 5s, HEALTH SAFETY ENVIRONMENTAL MANAGEMENT SYSTEM- FORMULATION- INTEGRATION- DOCUMENTATION- SUPPORT, AUDITS, EDUCATION AND TRAINING, OCCUPATIONAL EXPOSURE MEASUREMENT, CONTROL FORMULATION, LOCAL EXHAUST VENTILATION TESTING AND EXAMINATION.
LOCAL - NATIONAL - INTERNATIONAL
RISK ASSESSMENTS, HAZOP - FMEA- ETA- HRA STUDIES, 5s, HEALTH SAFETY ENVIRONMENTAL MANAGEMENT SYSTEM- FORMULATION- INTEGRATION- DOCUMENTATION- SUPPORT, AUDITS, EDUCATION AND TRAINING, OCCUPATIONAL EXPOSURE MEASUREMENT, CONTROL FORMULATION, LOCAL EXHAUST VENTILATION TESTING AND EXAMINATION
ADDING AND SUBTRACTING
SOUND LEVELS.
SUBTRACTION.
| INCREASE IN LEVEL WHEN | AMOUNT TO BE |
| SOURCE IS ADDED | SUBTRACTED FROM |
| TO BACKGROUND | MEASURED VALUE. |
| NOISE | |
| dB | dB |
| 3 | 3 |
| 4 to 5 | 2 |
| 6-9 | 1 |
| 10 and over | 0 |
Addition.
To add two levels in dB take the difference between them, read across column 1 to column 2 and add the figure to the higher of the values.
| 1 | 2 |
| Difference dB | Add to higher dB |
| 0 - 0.5 | 3 |
| 1.0 - 1.5 | 2.5 |
| 2.0 - 3.0 | 2 |
| 3.5 - 4.5 | 1.5 |
| 5.0 - 7.0 | 1 |
| 7.5 - 12 | 0.5 |
| > THAN 12 | 0 |
| A Weighting | |
| FREQUENCY | CORRECTION |
| Hz | dB |
| 31.5 | -39.2 |
| 63 | -26.1 |
| 125 | -16 |
| 250 | -8.6 |
| 500 | -3.2 |
| 1,000 | 0 |
| 2,000 | 1.2 |
| 4,000 | 1 |
| 8,000 | -1.1 |
| 16,000 | -6.5 |
