Document KRqJO78Bp6G50m8Nxmza82v1w

1107 lean National Standard Specification for Sound Level Meters, SI 4 (1971) Type S2A, and set to use the A-weighted net work with slow meter response Duration of exposure shall not exceed that shown m Table 10 These values apply to total duration of exposure per working day regardless of whether this is one continuous exposure or a number of short-term exposures but does not apply to impact or impulsive type of noise When the daily noise exposure is com posed of two or more periods of noise ex posure of different levels, their combined effect should be considered, rather than the individual effect of each If the sum of the following fractions exceeds unity, then, the mixed exposure should be considered to exceed the thresh old limit value, Ci indicates the total dura tion of exposure at a specific noise level, and Ti indicates the total duration of ex posure permitted at that level All on the job noise exposures of 80 dBA or greater shall be used m the above calculations Impulsive or unpact noise It is recommended that exposure to im pulsive or impact noise should not exceed 140 decibels peak sound pressure level Impulsive or impact noise is considered to be those variations in noise levels that involve maxima at intervals of greater than one per second Where the intervals are less than one second, it should be con sidered continuous TABLE 10 THRESHOLD LIMIT VALUES Duration per day Hours Sound Level dBA 16 80 8 85 4 90 2 95 1 100 Vi 105 Vi 110 % 115* * No exposure to continuous or intermittent m ex cess of 115 dBA * Sound level in decibels as measured on a sound level meter, conforming as a minimum to the requirements of the American National Standard Specification for Sound Level Meters, SI 4 (1971) Type S2A, and set to use the A-weighted network with slow meter response Ultraviolet Radiation The threshold limit value shall apply also to solar radiabon