Casella CEL CEL-296 - Manual (Page 22)

Figure 5: Comparison of CEL-493 and /2 with CEL-296 ranges
In either case, it an overload occurs during a measurement, move
the RANGE switch on the sound level meter to a higher range in
order to obtain valid readings.
MODE: Man/Ext - Scan – Recall
During measurement, this three position slide switch determines
whether autoscan, externally stepped, or manual stepped frequency
analysis is to be performed, It is also used later to recall results
stored in the memory, and show them on the display. Note that the
autoscan and storage facilities are available ONLY when connected
to sound level meters that are equipped with the CEL low power
serial interface.
The "Man/Ext" position is used when the centre frequencies are to
be stepped by pressing the and buttons, or when under the
control of an external recording device such as the CEL-238A. CEL-
338 and CEL-438 Printer/Loggers or CEL-160 Graphic Recorder.
Page 22 CEL-296/3 Operator Handbook CEL Instruments Ltd