dosemeter User Manual
Page 58
A standard time weighting applied by the Noise Measurement
Instrument
Sound Level Sound Pressure Level with a Frequency weighting, such as dB(A)
SPL Sound Pressure Level, the basic measure of noise loudness,
expressed in decibels
Time History A sample of the noise levels taken every 1 minute throughout the
measurement period.
Type 1 Laboratory & Field Grade for Sound Level Meters. Personal Noise
Dosemeters to the IEC 61252 Standard do not have a Class or
Type
Type 2 General Field Grade for Sound Level Meters. Personal Noise
Dosemeters to the IEC 61252 Standard do not have a Class or
Type
TWA Time Weighted Average. The daily personal exposure level
calculated from the L
AVG
and the measurement duration. TWA
replaces L
EP,d
in the OSHA Q=5 version of the dosemeter
L
AVG
The continuous A weighted sound level measured over the
measurement period with an exchange rate of 5dB. L
AVG
replaces
Leq in the OSHA Q=5 version of the dosemeter
% Dose The noise level measured expressed as a percentage of a fixed
level. For example, the reference 100% level would be a
continuous level of 90dB for 8 hours. The Criterion Time (CT) and
Criterion Level (CL) are used for the 8 hours and 90dB level
% Estimated Dose The % Dose projected forward over an 8 hour duration, assuming
that the noise level continued at the same level for the rest of the
8 hour reference period. The Criterion Time (CT) and Criterion
Level (CL) are used for the 8 hours and 90dB level
Exposure in Pa
2
hr The noise level measured expressed in as a linear term in Pa
2
hr
(Pascal Squared Hours). For example, a noise level of 94dB for 4
hours would be 1Pa
2
x 4 hours (94dB = 1Pa) giving an Exposure
of 4 Pa
2
hr. The 8 hour period is taken from the Criterion Time
(CT)
Estimated Exposure in
Pa
2
hr
The Noise Exposure above projected forward over an 8 hour
duration, assuming that the noise level continued at the same
level for the rest of the 8 hour period. The 8 hour period is taken
from the Criterion Time (CT)