doseBadge User Manual
Page 46
For example, some Regulations may mandate the use of 85dB for 8 hours as the limit
for a daily noise exposure. If the noise level was a constant 85dB for 8 hours, this
would generate a % Dose of 100%.
Estimated Dose
Estimates the % dose (described above) that would have been received by the wearer
if the average level measured had existed for the period defined by the criterion time.
For example, if for a 4 hour measurement the % Dose was 50%, the Estimated Dose
would be 100% for the 8 hours of the Criterion Time.
Threshold
Sound Levels below the threshold are excluded from all averaging.
For example, OSHA measurements use an 80dB threshold and call for a hearing
conservation program to be implemented when the eight hour TWA exceeds 85dB (50%
dose).
Criterion Level (CL)
In dB, the normalised eight hour average weighted sound level the corresponds to the
maximum permitted daily exposure or 100% noise dose.
Criterion Time (CT)
The time, in hours, used in the calculation of the % Dose and Estimated % Dose
measurement parameters. By default, this is set to 8 hours but can be configured to
other durations in the Reader unit.
Peak
The true peak level of the pressure wave (not the highest sound pressure level which is
termed the L
max
). The CR:112A doseBadge measures the true Peak level.
Overload
Indicated when the noise level exceeds the upper design limit of an instrument. In the
doseBadge this is set to 130dB(A) Sound Level
Glossary
A Weighting
A standard weighting of the audible frequencies designed to
reflect the response of the human ear to noise.
Acoustic Calibrator
An instrument that provides a reference noise source that is used
to calibrate and check the performance of a Sound Level Meter.
ANSI S1.25:1991
The American (US) Standard for Personal Sound Exposure Meters
(PSEM)
C Weighting
A standard weighting of the audible frequencies used for the
measurement of Peak Sound Pressure level.
