Casella CEL CEL-281 - Manual (Page 49)

Caution
When the instrument is restarted with the
key after data logging has been stopped by
pressing the + keys simultaneously,
the memory contents are cleared and all
previously stored data lost.
While in calibration delay or calibration modes, or if the display
has been switched off, this key combination will be ignored.
When the instrument is fully operational, this key combination
selects the upper STOP command on the key, switches the
RUN symbol off and stops logging data immediately, so that the
instrument enters the "stopped" mode (see Figure 5). The instru-
ment can be re-started only by pressing the key as de-
scribed in Section 3.3.4 below. This clears the memory, so that
all previously stored data will be lost.
+ (both keys pressed simultaneously)
When the instrument is fully operational and the RUN symbol is
displayed, while data is being logged, or when the display has
been switched off, this key combination will be ignored.
While in calibration delay mode, if the instrument has been
stopped, or if it is in any other display mode, this key combina-
tion selects the lower CAL command on the key, cancels the
other mode and enters calibration mode displaying A-weighted
sound pressure levels measured with the Fast time weighting.
Then pressing the or keys change the level displayed
over a range of ±2 dB so that the instrument can be calibrated
CEL-281 Operator's Handbook - Page 41
How It Works