DVM322DI GB
3
6. Operating Precautions
a) Wind blowing around the microphone causes additional extraneous noise. Mount the windscreen when
performing measurements under windy circumstances.
b) Recalibrate the instrument prior to use if it has not been used for some time or if it was last used in a difficult
environment.
c) Do not store or operate the instrument under excessive temperatures or humidity for a prolonged period of time.
d) Keep the microphone dry and avoid severe vibrations.
e) Remove the battery if the device is not to be used for several days.
7. Description of the Front, Side and Back Panels
1. Windscreen
Use the windscreen when the wind-force exceeds
10m/sec.
2. Display
See
“
8. Description of the LCD Display
” below.
3. Power & Backlight Button
Use
the -key to switch the device ON or OFF
or to turn the backlight ON or OFF. Press the
button once to turn the sound level meter ON and
press it again to turn on the backlight. Hold the
button for three seconds to deactivate the device.
4. MAX/MIN
Hold
Button
Press the MAX/MIN button to activate the MAX. & MIN. recording mode. Select the proper level range
beforehand to ensure that the readings will not fall outside the measurement range. Press once to select MAX
value. Press again to select MIN value. Press a third time to select the current value (MAX/MIN annunciator is
blinking). Hold the MAX/MIN button for two seconds to exit the MAX/MIN mode. Note that the MAX/MIN mode
will clear every time a different level range is selected or the operator alternates between A and C weighting.
5. REC
Button
Press the button to start recording. “REC” appears on the display. Press the button again to stop recording
6. Frequency Weighting Selection Button
A : A-weighting, for general sound level measurements.
C : C-weighting, to check the low-frequency content of the monitored noise. There is a large amount of low-
frequency noise if the value for the C-weighted level is much higher than that for the A-level.
7. Time Weighting Selection Button
FAST : for normal measurements
SLOW : for checking the average level of fluctuating noise.
8. Level Range Control Button
Press this button to select the various levels in this order : Lo
→
Med
→
Hi
→
Auto
→
Lo
→
…
9. Microphone
½” electret condenser microphone
10. CAL potentiometer
Calibration potentiometer used to calibrate the device.
11. RS-232 Interface
The RS-232 signal output is a 9600bps N 8 1 serial interface.
12. Signal Output Terminal
AC : 1 Vrms per range step. Output impedance = 100
Ω
. The output signal is transmitted via a standard
3.5mm coaxial socket. The signal is located on the pin
DC : Output : 10mV/dB. Output impedance = 1K
Ω
. The output signal is transmitted via a standard 3.5mm
coaxial socket. The signal is located in the middle.
