Velleman DVM322DI User Manual

DVM322DI -- SOUND LEVEL METER

1. Introduction and Safety Information

Thank you for buying the DVM322DI ! We advise you to read this manual thoroughly. You should only use this
device for the applications described in this manual. Unauthorised applications may cause damage to the device.

Environmental Conditions :

- Max. altitude : 2000m

- Max. relative humidity : 90%

- Operation temperature : 0 - 40°C

Maintenance

- All repairs and maintenance activities not described in this manual should be handled by qualified personnel.

- Wipe the housing clean from time to time with a dry cloth. Do not use abrasives or solvents on this device.

Safety Symbols

This device is EMC-compatible.

2. Features

This device was designed according to IEC651 type 2, ANSI S1.4 type 2 for sound level meters. The DVM322DI
meets the requirements of safety engineers and industrial safety offices for the monitoring of sound quality in various
environments.

- RS-232 interface with PC.

- data logging capacity with memory for 32000 measurements.

3. Specifications

Standards : IEC type 2, ANSI S1.4 type 2
Accuracy : ± 1.5dB (under conditions @ 94dB, 1KHz)

Frequency Range : 31.5Hz-8KHz
Measuring Level : 30-130dB
Frequency Weighting : A-C
Microphone : ½" electret condenser microphone
Digital Display : 4-digit LCD, resolution 0.1dB, display period 0.5sec.
Analogue Display : 50-segment bargraph, resolution 0.1dB, display period 50mS
Time Weighting : FAST = 125mS or SLOW = 1sec.
MAX/MIN Hold : To hold the highest and lowest values obtained during measurements
Level Ranges : a total of 4 ranges at step 10dB : 30-80dB, 50-100dB, 80-130dB, 30-130dB
Dynamic Range : 100dB
Alarm Function : OVER indicator (value is higher than the upper limit of the measuring range) and

UNDER indicator (value is lower than the lower limit of the range).

AC Output : 1Vrms at full scale

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Output impedance : 600Ω
FS (full scale= the upper limit of each range).
DC Output : 10mV/dB

Output impedance : ± 1KΩ
Power Supply : 1 x 9V-battery

Autonomy : ± 50hrs of continuous operation with an alkaline battery
DC adapter : Voltage 9VDC
Supply Current 30mA DC
Socket : pin = ground, housing = +, external Ø = 3.5mm, internal Ø = 1.35mm
Electromagnetic Compatibility : RF field = 3V/m, total accuracy = specified accuracy + 0.5dB
Operating Temperature : 0 to 40°C / 32 to 104°F
Operating Humidity : 10 to 90%
Storage Temperature : -10 to +60°C / 14 to 140°F
Storage Humidity : 10 to 75%
Memory Size : 32000 measurements
Dimensions : 10.8 (L) x 2.5 (W) x 1.2 (H) inch // 275 (L) x 64 (W) x 30 (H) mm
Weight :
Accessories : 9V-battery, carrying case, screwdriver, user manual, windscreen, 3.5mm plug, RS-

285g (including battery)

±

232 cable, software for Windows.

4. Calibration

Use a standard sound level calibrator (OPTION DVM1356).

1. Use the following settings :
Display : dBA
Time Weighting : FAST
Measurement Mode : MAX MIN function deactivated
Level Range : 50 to 100dB

2. Connect the microphone with the calibrator through the
microphone connection of the DVM322DI.

3. Activate the calibrator and adjust the CAL potentiometer. The
display will indicate the desired level range. This device has
been calibrated by the manufacturer. Maximum accuracy can
be expected during a one-year period after calibration.
Consequently, the device should be recalibrated every twelve
months.

acoustic calibrator

screwdriver

5. Preparing for Measurements

a) Inserting the battery : Remove the battery cover at the back of the device and insert one 9V-battery.

Observe the polarity indications inside the battery compartment !

b) Replacing the battery : The
c) Connecting an DC adapter : Connect the OPTIONAL adapter (PSU03R) with the DC 9V connector of the

DVM322DI's side panel.

DVM322DI GB

-symbol will flash on the display when the battery needs to be replaced.

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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

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 = 100Ω. The output signal is transmitted via a standard

DC : Output : 10mV/dB. Output impedance = 1KΩ. The output signal is transmitted via a standard 3.5mm

-key to switch the device ON or OFF

3.5mm coaxial socket. The signal is located on the pin

coaxial socket. The signal is located in the middle.

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