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Section 8 Glossary & Terminology
The following section lists the acoustic terminology that is found in this manual and in
the CR:112A doseBadge Personal Noise Dosimeter and RC:112A Reader Unit. For
further information, please contact your local representative or Cirrus Research plc
directly.
Terminology
The doseBadge and Reader can produce the following metrics as defined in the relevant
standards. Some of these are available on the Reader display, others require a printer
or the computer software supplied.
When the data is downloaded from the RC:112A Reader unit to the doseBadge
software, the following parameters are provided:
L
AVG
L
is the average Sound Level over the measurement period when the exchange rate
AVG
(Q) is other than 3dB or where there is a Threshold applied or a Time Weighting
applied.
L
is the equivalent of L
AVG
Threshold value is used during the calculation of L
threshold not being included.
For example:
Assume the threshold level is set to 80dB and the exchange rate is 5dB (which are the
settings for OSHA's Hearing Conservation Amendment). If a one hour measurement
was taken in an environment where the noise levels varied between 50dB and 70dB,
the sound level would never exceed the threshold level and the instrument would
record no value for the L
few seconds, then only these seconds would contribute to the L
around 40dB which is much lower than the actual ambient sound levels in the
environment.
TWA
The Time Weighted Average is the average of the measured L
period. The TWA will be lower than the L
than eight hours, equal to the L
the L
for measurements over eight hours.
AVG
% Dose
A percentage of a fixed dose value based on the criterion level and criterion time. The
criterion level and time are set by local standards.
doseBadge User Manual
for exchange rates other than 3dB, for example Q=5. The
eq
. If the sound level exceeded the 80dB threshold for only a
AVG
AVG
for a measurement of eight hours, and higher than
AVG
with any levels below the
AVG
AVG
when the measurement duration is less
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giving a level of
AVG
over an eight hour
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