The OSHA noise regulations define action
levels (85 and 90 dBA Time Weighted Average, or 50% and 100% Dose)
that are based on a worker's daily exposure to noise - they
are not based on simple snap-shots of the noise level. The worker's
noise exposure can be measured using a Noise Dosimeter such as
the doseBadge,
which is worn throughout the working day. Otherwise, you can use
a sound level meter to
measure the average sound level at each location that the
person is working at during a typical day.
To use the TWA and Dose Calculator,
make noise measurements at each location and make note of how long
the person works there. Enter these levels into the calculator.
In the example above, the person works for four hours at Machine
1, two hours at Machine 2 and two hours at Machine
3, making a total of 8 hours. The worker's Noise Dose
is 209% and TWA is 95.3 dB.
The colour coding on the screen are:
Black
Level is below the first action level.
Red
Level is above the first action level but below the second
action level.
Red Bold
Level is above the second action level.
It is clear above that reducing the noise at Machine 2 will
have the greatest influence on the daily noise dose.
The calculator will accept sound levels between 40 and 140 dB.
Exposure times can be up to 24 hours at each location with a limit
of 24 hours on the total exposure time.
