Casella CEL CEL-281 - Manual (Page 90)

5. If the instrument is fully operational while the RUN legend is
displayed continuously to indicate that data is being logged, go
to step 6, but note the following Caution.
Caution
When the instrument is restarted with the
key after data logging has been stopped, the
memory contents are cleared and all
previously stored data lost. To preserve the
data, download to a PC before restarting.
6. When the instrument is logging data (with RUN legend dis-
played continuously), press the + keys simultane-
ously to stop logging, then go to step 8.
7. If the instrument is already fully operational but the display has
been switched OFF, press the key to switch the display
ON.
8. With the instrument switched ON, and fully operational with the
display ON but no data currently being logged (RUN legend not
shown), press the key to change the frequency weighting
from the currently indicated choice.
This key has a toggle operation, so pressing it will always select
the other frequency weighting option (i.e the one not currently
displayed).
Until changed again, the newly displayed frequency weighting value will
be used in all measurements. It will also be stored for use the next time
the instrument is switched ON.
Preparation
CEL-281 Operator's Handbook - Page 81