Instruction manual

Casella CEL-35X dBadge Users Handbook – Page 38
the pressure wave, which should not be confused with the highest
sound pressure level, termed Lmax.
Slow Time Weighting
A standard time weighting applied by the noise measurement
instrument.
SPL
The sound pressure level. This is the basic physical measure of noise,
and is normally expressed in dB.
Threshold
A threshold below which sound levels are excluded from calculation.
OSHA measurements use an 80 dB threshold and call for a hearing
conservation program to be implemented when the eight hour TWA
exceeds 85 dB (50% dose).
TWA
This is a parameter used in OSHA measurements. The time weighted
average is the daily personal exposure level calculated from the LAVG
and measurement duration.
Z-Weighting
Effectively this is a linear, or un-weighted measurement. In the
dBadge system it is used for the measurement of peak sound
pressure level against the OSHA standard.