Casella CEL CEL-368 - Manual (Page 29)

In practice, the main limitations on cumulative duration will be manually
timing an interval shorter than one minute, or the availability of sufficient
memory to store all of the L
n values determined during a long term
measurement. Memory space is reserved for the cumulative results so
that, provided there is sufficient power, they will always be saved.
Four sets of cumulative results (four logging runs) can be stored, where
results become available only AFTER the run is complete. The following
cumulative information is determined and stored for each run:
• Cumulative store (run) identity,
• Time when cumulative period started (to nearest minute),
• Duration of cumulative period,
• Measurement settings (time and frequency weightings),
• Maximum sound pressure level attained during run (sometimes
known as L
max or L n0 value),
• L eq - equivalent continuous level calculated over the duration of
the whole run,
• Up to four user pre-selected L n values,
• L Avg - average noise level calculated over the duration of the
whole run with any separately selected Q value,
• Whether logging has been paused by pressing during
the run,
• Whether 200 Pa level was exceeded during the run (70 - 140 dB
range only),
• Whether overload occurred during the run,
• Whether the battery volts fell below 3.6 V during the run.
Period:
A period interval is always set (even when period data is not required).
In period mode, a series of measurements will be made, and results cal-
culated and stored at regular intervals (periods) set by the user. Periods
of 1 min, 5 min, 10 min, 15 min, 30 min, and 60 min can be set. A maxi-
mum of 999 period results can be collected during each logging run, and
RUN
PAUSE
CEL-268/368 Operator's Handbook - Page 25