Casella CEL CEL-281 - Manual (Page 37)

calibration delay period, during which the operator can elect to perform a
calibration. If no calibration is initiated within this period, the instrument
will become fully operational using the calibration and time weightings
used for the previous operation.
The other functions and operations shown connected to the "operational"
box by solid lines are available at any time, while functions connected by
dotted lines become available only when the instrument has been
stopped.
3.1.2 Level
This area produces information about noise levels which can be pre-
sented in terms of dB, or Pa
2
h energy units.
Sound pressure levels and maximum sound levels with fast or slow time
weightings are available plus the time and date when the maximum oc-
curred.
Average levels are also available calculated with different exchange rates
Q (including L
eq with 1 minute averaging period and Q = 3), and with vari-
ous threshold levels.
3.1.3 Time Information
This area yields information about the current time and date.
The instrument can display the period that has elapsed since the current
measurement session started, the proportions of overload and under
range during this period (in %). It can also indicate whether the peak ac-
tion level of 200 Pa = 140 dB specified by recent European noise expo-
sure legislation has been exceeded, and indicate the earliest and most
recent times and dates at which this event occurred.
3.1.4 Distribution
This area determines and stores statistical information, so that the cumu-
lative percentage and probability percentage of sound pressure levels
and maximum sound levels with fast or slow time weightings are avail-
CEL-281 Operator's Handbook - Page 29
How It Works