Circuit-test DMS-4400 User manual

DMS-4400
1
DMS-4400
SOUND LEVEL METER
CIRCUIT-TEST

DMS-4400
1
DMS-4400
Contents
1. General Description & Specifications ............ 1
2. Name and Functions ...................................... 3
3. Calibration Procedures .................................. 6
4. Measurement Preparation ............................. 7
5. Operating Precautions ................................... 7
6. Measurement ................................................. 8

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To ensure proper use of this Sound Level Meter, we
recommend that you read and follow this manual
carefully.
This unit conforms to the IEC61672 Type2, ANSI S1.4
Type2 for Sound Level Meters.
This Sound Level Meter has been designed to meet the
measurement requirements of safety Engineers, Health,
Industrial safety offices and quality control in various
environments.
 Ranges from 30dB to 130dB at frequencies between
31.5Hz and 8 KHz.
 Display with 0.1dB steps on a 4 digits LCD.
 With two equivalent weighted sound pressure levels,
A and C.
1. GENERAL DESCRIPTION &
SPECIFICATIONS
a. Display:4 digits LCD with maximum/minimum,
Resolution:0.1dB, Display Update:0.5 sec.
b. Standard applied:IEC61672 Type2, ANSI1.4
Type2.
c. Frequency range:31.5Hz~8KHz.
d. Measuring level range:A Weighting 30 ~130dB.
C Weighting 35~130dB.
e. Frequency weighting:A/C.
f. Microphone:1/2 inch Electret condenser
microphone.
g. Time weighting:FAST (125mS),SLOW (1 sec).
h. Level ranges:30 ~130dB (Auto Range).
i. Accuracy: 1.5dB.
j. Dynamic range:50dB.

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k. MAX/MIN:Hold readings for the Maximum and
Minimum value.
l. DATA HOLD:The reading data shown on LCD can
be locked while pressing the button
m. Low Battery Indication: Replace battery as LCD
display “ ”.
n. Power Supply:9V NEDA 1604, IEC 6F22, JIS 006P
battery×1pcs.
o. Power Life: About 50 hrs (Alkaline Battery).
p. Operating Altitude: Up to 2000M.
q. Operating temperature & Humidity: 5C~40C,
below 80RH.
r. Storage Temperature & Humidity: -10C ~60C,
below 70RH.
s. Dimension: 200mm(L)x55mm(W)x38mm(H).
t. Weight: About 170g. (Including batteries)
u. Accessories: Instruction manual, carrying case, 9V
Battery & windscreen.

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1. Windscreen
2. Display
3. DATA HOLD button
4. Frequency weighting
select button
5. Time weighting select
button
6. Maximum/Minimum
hold button
7. Backlight button
8. Power button
9. Microphone
10. Battery Cover
11. Tripod socket
2. NAME AND FUNCTIONS
1. Windscreen
If operating at wind speeds of over 10m/sec,
please put protective accessory windscreen in
front of the microphone.
4
7
1
2
5
6
8
9
10
3
11

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a. Low battery indicator
b. DATA HOLD
indicator
c. Maximum indicator
d. Minimum indicator
e. A-Weighting
f. C-Weighting
g. Slow response
h. Fast response
i. Sound level read out
2. Display
3. DATA HOLD button
Readings shown on the LCD can be locked while
pressing this button.
4. Frequency Weighting select button
A: A-Weighting for general sound level
measurements. C: C-Weighting for checking the
low-frequency content of noise (If the C-Weighted
level is much higher than the A-weighted level,
then there is a large amount of low-frequency
noise).
5. Time weighting select button
FAST: for normal measurements.
SLOW: for checking average level of fluctuation
noise.
a
b
c
d
e
f
h
g
i

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6. MAX/MIN hold button
6.1 Press the key to activate the function. The “MAX”
symbol appears on the display and the instrument
will show the Maximum value measured and will
automatically update itself when a greater value is
measured.
6.2 Press the key again and the “MIN” symbol
appears on the display and the instrument will
show the Minimum value measured and will
automatically update itself when a lower value is
measured.
6.3 The MAX/MIN function will be disabled if the
MAX/MIN button is pressed for more than 1
second or if the meter is turned off.
7. Backlight button
Press the button to enable the display backlight
for easy readings in dark environments. Press
more than 1 second to disable backlight or wait
and it will automatically turn OFF after 15
seconds.
8. Power button.
Press key for 1sec to turn the sound level meter
ON or OFF. The unit will power off automatically
after 5 minutes of idle time.
9. Microphone
1/2 inch Electret Condenser microphone.
10. Battery cover

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3. CALIBRATION PROCEDURES
Using a standard Acoustic Calibrator (94dB, 1 KHz Sine
wave)
1. Make the button settings display: dBA
Time weighting: FAST
2. Insert the Microphone nozzle carefully into the
insertion hole of the calibrator.
3. Press the A/C and the HOLD button simultaneously
for more than 1 second and the LCD will start
blinking to confirm calibration.
Acoustic calibrator
Sound level meter

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4. When the LCD stops blinking, release the A/C and
the HOLD buttons. The sound level meter will
display 94.0 dBA when the calibration is done.
5. The 94 dB calibration process can be repeated until
the meter reads 94.0 dB. Recalibration cycle: 1 year.
4. MEASUREMENT PREPARATION
1. Battery Loading
Remove the battery cover on the back and put in a
9V Battery.
2. Battery Replacement
When the battery voltage is low, the following
symbol appears; this indicated that the battery
needs to be replaced.
5. OPERATING PRECAUTIONS
1. Air blowing across the microphone can cause noise
and interference when using the instrument in
windy environments, use the windscreen to reduce
noise.
2. Calibrate the instrument before operation if the
instrument was not in use for a long time or
operation at bad environment.
3. Do not store or operate the instrument at high
temperature and high humidity environment.
4. Keep microphone dry and avoid severe vibration.
5. When the instrument is not used for an extended
period of time, remove the battery and store the unit
in a low humidity environment.

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6. MEASUREMENT
1. Open battery cover and install a 9 Volt battery in
battery compartment.
2. Turn on power and select the desired response
time and weighting. If the sound source consists of
short bursts or only catching sound peak, set
response to FAST. To measure average sound
level, use the slow setting. Select A weighting for
general noise sound level and C weighting for
measuring sound level of acoustic material.
3. Hold the instrument comfortably in hand or fix on
tripod and point the microphone at the suspected
noise source, the sound pressure level will be
displayed.
4. When MAX/ MIN (maximum, minimum hold) mode
is chosen. The instrument captures and holds the
maximum or minimum noise level. Press once to
select MAX value. Press again to select MIN value,
Press again to exit the MAX/MIN mode. “MAX” or”
MIN” symbol disappears.
5. Turn off the instrument and remove the battery
when not in use.

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