Instruction manual

8
Controls and Functions
CAL key
Pressing this key activates the built-in oscillator for electrical calibration of the NA-27
or for level matching of the NA-27 and connected equipment.
FREQ WEIGHT key
Selects the frequency weighting characteristic for the main channel. Available settings
are "A" weighting (A), "C" weighting (C), and flat frequency response (FLAT).
The frequency weighting characteristics for the sub channel are set with the SETUP
menu screen.
TIME CONST key
Selects the time weighting (time weighting) for the main channel. Available settings
are "FAST", "SLOW", "35 ms" and "10 ms". The time weighting for the sub channel is
set with the SETUP menu screen.
LEVEL UP LT key
Serves to select the level range. The level range cannot be set individually for the main
channel and sub channel. When showing the level-time display (from data stored in the
internal memory), the key serves to expand the time axis.
LEVEL DOWN LT key
Serves to select the level range. The level range cannot be set individually for the main
channel and sub channel. When showing the level-time display (from data stored in the
internal memory), the key serves to contract the time axis.
STORE key
Serves to start and stop the store process for entering data into the memory.
RECALL key
Switches the unit between the mode for recalling data from the memory (recall mode)
and the measurement data display mode (current mode).
INC, DEC keys
Serve to increase or decrease numerical values of the various menu entry items. When
data are being stored into the memory or displayed from memory, the keys serve to
select address numbers.
keys
Serve to select items from the menu screens.