Rion NA-42, Instruction Manual

Page: 34 / 122

24
Preparations
2) Calibration with pistonphone NC-72 or sound calibrator NC-74
For this type of calibration, the pistonphone NC-72 or sound calibrator NC-74
is mounted on the microphone and the sensitivity control is adjusted so that
the sound pressure level indication matches the sound pressure level in the
coupler.
Important
Insert and remove the microphone into and
from the pistonphone NC-72 or sound calibra-
tor NC-74 very slowly and carefully, since the
pressure change could otherwise damage the
diaphragm of the microphone.
1. Turn power to the pistonphone NC-72 or sound calibrator NC-74
off.
2. Turn power to the NA-42 on.
3. Press the SENS key on the front panel.
SOUND LEVEL
MEASURING AMPLIFIER
HPF LPF
LEVEL RANGE
CAL
20dB/50dB
POWER
EXT FILTER RESET
L
p/
L
max
/
L
peak
ON
INPUT
NA-42
ADJ
FAST
SENS
MENU
A/C
/FLAT
/SLOW
/IMP
(LIGHT)
20Hz 20kHz
20Hz 20kHz
LEVEL RANGE keys
Sensitivity control
POWER switch
Setting up/down keys
SENS key