Circuit-test DMS-4420 User manual

DMS-4420
Sound Level Meter Datalogging
CIRCUIT-TEST

CIRCUIT-TEST DMS-4420

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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
7. System requirements................................9
8. User End Menu.........................................10

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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
31.5HZand 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:IEC651 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.
k. MAX/MIN:Hold readings for the Maximum and
Minimum value.

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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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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. REC response
j. Sound level readout
1. Windscreen
2. Display
3. HOLD button
4. Frequency weighting select
button
5. Time weighting select button
6. Maximum/Minimum hold
button
7. Backlight button
8. Power button
9. REC button
10. RS-232 Interface Connector
11. Microphone
12. Battery Cover
2. NAME AND FUNCTIONS
1. Windscreen
If operating at wind speeds over 10m/sec, please
put protective accessory windscreen in front of the
microphone.
2. Display
USB Interface Connector

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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.
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.

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7. Backlight button
Press this button to enable the backlight display
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 auto power will be off
automatically after 5 minutes idle time.
9. REC button
Press the button to start recording data and press
REC again to stop recording.
The minimal interval is 1 second and the
maximum interval time is 7 Hours 59 Minutes 59
Seconds. Total Records: 14.000.
10. RS-232 Interface Connector
RS-232 interface with a computer.
11. Microphone
1/2 inch Electret Condenser microphone.
12. Battery cover
USB Interface Connector
USB interface with a computer.

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3. Calibration Procedures
Using a standard Acoustic Calibrator (94dB, 1KHz 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.
4. When the LCD stops blinking, release the A/C and
Acoustic calibrator
Sound level meter

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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
one 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 in a high
temperature or 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 it is not in use.

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7. System requirements
1. The User End package contains
Custom designed RS-232 cable
2. System Required
Windows 2000, Windows XP
3. Minimum Hardware Required
Pentium III 500MHZ PC compatible, or above
128MB RAM; At least 10MB hard disk space
available to install User End program.
Recommended display resolution is 800X600 or
above.
USB cable

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8. User End Menu
1. Tool Bar
Tool bar section has 6 buttons:
[Connect To Meter] [Download All Records]
[Erase All Records] [Update Meter Date/Time]
[Save Records to File] [Print]
Use button [Connect to meter] to connect meter to PC.
This step is the first step before running the software.
Use button [Download All Records] to download records
from Meter to Local computer.
Use button [Erase All Records] to erase all the records
saved in memory.
Use button [Update Meter Date/Time] to synchronize
the time in meter with the computer. Remember if the

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battery is taken out, the clock in the meter will stop.
Use button [Save Records to File] to export the records
from the list box to txt file. This button will be enabled
after downloading records.
Use button [Print] to print all the downloaded data.
2. Real time Data
Real time data section is used to display real time data
including DB value, dba/dbc status, fast/slow status,
hold, rec, max/min status.
Current meter situation including total group and total
records in the memory, interval, meter date and time,
are also displayed at the left side.
3. Group information Data
The Group information data section is used to display
selected group information including start time, end
time, dBA/dBC status and record number in selected
group.
4. Status Message

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