Casella CEL CEL-368 - Manual (Page 38)

If the first active time is a stop (end) time, the instrument will start log-
ging data immediately and stop logging when the stop time is reached.
However, if the first active time is a run (start) time, the instrument will
wait until this time is reached before starting to store data. Then data
logging will be concluded at the next active stop time. When there is no
active stop time, the instrument will continue to log data until manually
stopped.
The timer allows delays from 0 minutes to 23 hours 59 minutes before
starting the next cumulative run, and run durations between 1 minute
and 24 hours to be set. For example, when a stop time is set to the
same time as a preceding run time, the run will end 24 hours after the
start.
When the run time is set to the same time as the preceding stop time, a
new logging run will start immediately the preceding run stops. This
makes it possible to obtain a continuous logging run with the overall du-
ration divided between the separate cumulative stores, each with its
own period and event results. Any total duration between 4 minutes and
4 days can be achieved. It is also possible to obtain delays longer than
23 hours, 59 minutes by setting long delay times between "dummy" 1 m-
inute runs until the overall delay is achieved. This can produce a 4 day
delay (less 1 minute) that allows a weekend to be skipped.
Timer operations are summarized in Figures 8 & 9, Section 6.4.
To extend the battery life when the timer is ON but the instrument is not
logging data (WAIT status), the instrument switches to a low power
state using approximately 10% of its normal consumption. If there is
doubt whether the batteries will be able to power the instrument for the
times set, a suitable external power supply should be arranged as de-
scribed in Section 4.11.
4.8 Control Keys
The functions of the control keys are identified by the legends marked
on them (see Figure 4).
Figure 3: Typical
Display
Page 34 - CEL-268/368 Operator's Handbook