Casella CEL CEL-35X dBadge - Manual (Page 36)

Casella CEL-35X dBadge Users Handbook – Page 36
Decibel (dB)
The standard physical unit for measuring sound level and noise
exposure.
Estimated Exposure in Pa
2
h
A calculated estimate of the exposure that would be received by the
wearer if the average level measured continues for the period defined
by the criterion time. Expressed in Pascal squared hours (Pa
2
h).
Fast Time Weighting
A standard time weighting applied by the sound level measurement
instrument.
IEC 61252
The International Standard for Personal Sound Exposure Meters.
LAE
The A-weighted exposure level is the level that would contain the
same amount of energy in one second as the actual noise has during
the whole measurement period.
LAeq
The A-weighted equivalent level is the level that would contain the
same amount of noise energy as in the actual noise, effectively giving
an average level over the measurement period. Following the ISO
procedures, doubling the energy results in a 3dB change in the Leq.
This is denoted by exchange rate Q=3. For example, if the noise level
in a factory was a constant 85dB and the measurement period was 4
hours, the LAeq would be 85dB(A). The calculation of LAeq DOES
NOT USE a Threshold as in the calculation of LAVG.
LAF
The A-weighted sound level measured with Fast time weighting.
LAS
The A-weighted sound level measured with Slow time weighting.
LASmax
The maximum A-weighted sound level measured with Slow time
weighting.