Velleman DVM 68 User manual

DVM 68
LCD Auto Range Digital Multimeter
OPERATION MANUAL
GEBRUIKERSHANDLEIDING
MANUEL D’UTILISATEUR

VELLEMAN GB1
DVM 68
LCD Auto Range Digital Multimeter
1. Description
Your DVM 68 is a autoranging professional digital multimeter with a 3 ¾ digit LCD
display. It is ideally suited for field, lab, shop, and home applications. By using the
latest in IC and display technology to significantly reduce the number of discrete
internal components, the multimeter gives you superb measuring capability as well as
the highest possible reliability.
It is capable of performing functions :
DC Voltage AC Voltage Resistance
AC Current DC Current Capacity
Frequency Continuity
Also diodes and transistors (amplification hFE) can be tested.
1.1 Warning
Use extreme caution in the use of this device. Improper use of this device can result in
injury or death. Follow all safeguards suggested in this owner's manual in addition to
normal safety precautions in dealing with electrical circuits. Do not use this device if
you are unfamiliar with electrical circuits and testing procedures.
Not for commercial or industrial use.
1.2 A word about safety
This multimeter is designed to ensure the safest operation possible. However, safe
operation depends on you, the operator. Make sure you follow these simple safety
rules :
• Never apply a voltage to the multimeter that exceeds the limits given in the
specifications. Never apply more than 1000V DC or 750V rms AC between an
input jack and ground.
• Use extreme caution when working with voltages above 60V DC or 30V AC rms.
• Always discharge filter capacitors in the power supply circuit under test before you
attach test leads.
• Never connect to a source of voltage when you select DCA, ACA, resistance
measurement or continuity check function.
• Always turn off power and disconnect the test leads before you replace the batteries
or fuse.
• Never operate the multimeter unless the battery cover is in place and fully closed.
When carrying out measurements on TV or switching power circuits, always
remember that there may be high amplitude voltages pulses at test points which can
damage the meter.

VELLEMAN GB2
1.3 Maintenance
Your DVM 68 is an example of superior design and craftsmanship. The following
suggestions will help you care for themultimeter so you can enjoy it for years :
• Keep the multimeter dry. If it gets wet, wipe it dry immediately.
• Use and store the multimeter only in normal temperature environments.
Temperature extremes can shorten the life of electronic devices or damage
batteries.
• Handle the multimeter gently and carefully. Dropping it can damage the circuit
boards and case and can improper functioning.
• Use only fresh batteries of the required size and type. Always remove old or weak
batteries.
If you do not plan to use the multimeter for a month or more, remove the batteries.
This protects the multimeter from possible leakage.
• Disconnect the test probes before opening the multimeter.
• Replace blown fuses only with same size and type :
F1 : F 300mA/250V F2 : F 10A/250V
• If any faults or abnormalities are observed, do not use this device and let it check
by authorised personel.
• Never use the meter unless the back cover is in place and fastened fully.
• To clean the meter, use a damp cloth and mild detergent only, do not use abrasives
or solvents.
2. Description of the front panel
1. Display
2. Range Control Button
3. Data Hold button
4. AC/DC Current of
/ Selecting Button
5. Socket for Transistor Test
6. Function Switch/Power Switch
7. V/Ω/F Input Jack
8. COM Input Jack
9. mA/Cx Input Jack
10. 10A Input Jack
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VELLEMAN GB3
2.1 Range Control Button
Range for AC/DC voltage, AC/DC current(µA and mA only), Resistance and
Frequency measuring can be selected manually or autorange. Push this button as
following to choose range the desired mode or range.
2.2 DATA HOLD button
When this button is pushed, the display will show the last reading and " D-H " symbol
will appear until the button is pushed again.
Data holding will be cancelled automatically when the function switch is rotated.
2.3 AC/DC Current or / Selecting button
Push this button to select AC or DC current measuring function when the function
switch is set at µA, mA, A positions.
Push this button to select or measuring when the function switch is set at /
position.
Power On or Function Changing
AutoRanging
Manual Ranging
Range Changed
Push button
for over
3 sec.
Push button once
"R-H"displayed
Push button for
less than 1 sec.

VELLEMAN GB4
2.4 Input Jacks
This meter has four input jacks that are protected against overload to the limits.
During use, connect the black test lead to the COM jack and the red test lead as shown
below
Function Red Lead Connection Input Limits
DCV / ACV V / Ω/ F 1000V DC or 750V AC rms
kHz V / Ω/ F 250V DC or AC rms
Ω/ / V / Ω/ F 250V DC or AC rms
µA / mA mA / Cx 300mA DC or AC rms
nF / µF mA / Cx 300mA fuse protected
A A 10A DC or AC rms
µA/ mA and A ranges are protected by fuses.
3. Operating instructions
3.1 Measuring Voltage
1) Connect the black test lead (-) to the COM jack and the red test lead (+) to the
V/Ω/F jack.
2) Set the function switch at V or V∼range to be used and connect test leads across
the source or load under measurement.
3) Read LCD display. The polarity of red connection will be indicated when making a
DC measurement.
3.2 Measuring Current
1) Connect the black test lead (-) to the COM jack and the red test lead (+) to the
mA/Cx jack for a maximum of 300mA. For a maximum of 10A, move the red lead to
the A jack.
2) Set the function switch at µA, mA or A range to be used and push / ∼button to
select DCA or ACA mode.
3) Connect test leads IN SERIES with the load in which the current is to be
measured.
4) Read LCD display. The polarity of red lead connection will be indicated when
making a DC measurement.
3.3 Measuring Resistance
1) Connect the black test lead (-) to the COM jack and the red test lead (+) to the
V/Ω/F jack.
2) Set the function switch at Ωrange to be used and connect test leads across the
resistance under measurement.

VELLEMAN GB5
Remarks :
1) For resistance above 3.26MΩ, it may take a few seconds to stabilize reading. This
is normal for high resistance measuring.
2) When the input is not connected, i.e. at open circuit, the figure "OL" will be
displayed for the overrange condition.
3) When checking in-circuit resistance, be sure the circuit under test has all power
removed and all capacitors are fully discharged.
3.4 Measuring Capacitance
1) Connect the black test lead (-) to the COM jack and the red test lead (+) to the
mA/Cx jack.
2) Set the function switch at nF or µF position to be used.
3) Connect test leads across the capacitor under measurement and be sure that the
polarity of connection is observed.
Remarks :
1) When checking in-circuit capacitance, be sure that the circuit has all power
removed and all capacitor are fully discharged.
2) The range control mode in capacitance measurement is manual ranging and only
two ranges (326nF, 32.6µF) are provided.
3) If Range Control Button is used in this measuring function, decimal points may be
at incorrect positions.
4) At the nF range, when the capacitor to be measured is not connected to test leads,
the LCD may not read zero, but a few counts. These count have to be substracted from
measuring results.
3.5 Measuring Frequency
1) Connect the black test lead (-) to the COM jack and the red test lead (+) to the
V/Ω/F jack.
2) Set the function switch at the Hz position and connect test leads across the source
or load under measurement.
Remark :
The input voltage should be between 200mV and 10V rms AC. If the voltage is more
than 10V rms, reading may be out of the accuracy range.
3.6 Continuity & Diode Test
1) Connect the black test lead to the COM jack and the red test lead to the V/Ω/F jack.
2) Set the function switch at / position and push the /button to select
continuity or diode test mode.
3) In continuity testing, if continuity exists (i.e. resistance less than about 50Ω), built-
in buzzer will sound.
4) If diode test mode is selected, connect the red and black to the anode and cathode
of the diode under test. The forward voltage drop of this diode in V will be displayed.

VELLEMAN GB6
3.7 Transistor Test
1) Set the function switch at hFE position.
2) Identify whether the transistor is NPN or PNP type and locate emitter, base and
collector lead. Insert leads of the transistor to be tested into proper holes of the testing
socket on the front panel.
3) LCD display will show the approximate hFE value at the test condition of base
current 10 µA and Vce 3.2V.
4. Specifications
Accuracy is specified for a period of one year after calibration and at 18°C to 28°C
with relative humidity to 80%.
4.1 General
Max. voltage between terminal and earth 1000V DC or 750V AC rms (sinus)
Display 3 ¾ digit LCD, 3260 counts max,
2-3 readings / sec
Fuse protection µA & mA range : F 300mA/250V
A range : F 10A/250V
Power Supply 9V battery
Ranging method Auto / Manual
Polarity indication " - " displayed
Overrange indication " OL " displayed automatically
Low Battery indication " " displayed
Operating temperature 0°C to 40°C
Storage temperature -10°C to 50°C
Dimensions 91 x 189 x 31.5 mm
Weight 310 g (incl. battery)
4.2 DC Voltage
Range Resolution Accuracy
326mV 0.1mV ±0.5% of rdg ±2 digits
3.26V 1mV
32.6V 10mV ±0.3% of rdg ±2 digits
326V 0.1V
1000V 1V ±0.5% of rdg ±2 digits
Input impedance : 10MΩ, more than 100MΩat 326mV range

VELLEMAN GB7
4.3 AC Voltage
Range Resolution Accuracy
3.26V 1mV
32.6V 10mV ±0.8% of rdg ±3 digits
326V 0.1V
750V 1V
Input impedance : 10MΩ
Frequency range : 40 to 1000Hz, 40 to 200Hz at 3.26V range
4.4 DC Current
Range Resolution Accuracy Burden Voltage
326µA 0.1µA 0.5mV / µA
3260µA 1µA ±1.2% of rdg ±3 digits 0.5mV / µA
32.6mA 10µA 8.0mV / mA
326mA 0.1mA 8.0mV / mA
10A 10mA ±2.0% of rdg ±5 digits 0.02V / A
Overload protection : F 300mA fuse for µA and mA ranges,
F 10A fuse for A range
4.5 AC Current
Range Resolution Accuracy Burden Voltage
326µA 0.1µA 0.5mV / µA
3260µA 1µA ±1.5% of rdg ±5 digits 0.5mV / µA
32.6mA 10µA 8.0mV / mA
326mA 0.1mA 8.0mV / mA
10A 10mA ±3.0% of rdg ±7 digits 0.02V / A
Overload protection : F 300mA fuse for µA and mA ranges,
F 10A fuse for A range
Frequency range : 40Hz to 1000Hz
4.6 Resistance
Range Resolution Accuracy
326Ω0.1Ω±0.8% of rdg ±3 digits
3.26kΩ1Ω
32.6kΩ10Ω±0.8% of rdg ±3 digits
326kΩ100Ω
3.26MΩ1kΩ
32.6MΩ10kΩ±1.2% of rdg ±2 digits
Maximum Open Circuit Voltage : 1.3V
4.7 Capacitance

VELLEMAN GB8
fig. a fig. b fig. c
fig. d
Range Resolution Accuracy
326nF 0.1nF ±3.0% of rdg ±5 digits
32.6µF 10nF
4.8 Frequency
Range Resolution Accuracy
32.6kHz 10Hz ±1.2% of rdg ±3 digits
150kHz 100Hz ±2.5% of rdg ±3 digits
Sensivity : 200mV rms up to 50kHz, 1V rms for 50kHz to 150kHz
5. Accessories
Test leads
Battery (9V)
Operation Manual
Holster
5.1 How to use the holster
The holster is used to protect the meter and to make the measurement more
confortable. The following figures shows how to use the holster to :
1) Support the meter with a standard angle. (fig. a)
2) Support the meter with a small angle using the little stand.(fig. b)
3) Hang the meter on the wall using the little stand. (fig. c)
Take the little stand off from the back side of the large stand and insert it into holes
located upper on the holster.
4) Hold test leads. (fig. d)
6. Battery and fuse replacement

VELLEMAN GB9
If the sign " " appears on the LCD display, it indicates that the battery should be
replaced. Remove screws on the back cover and open the case. Replace the exhausted
battery with a new one.
Fuse rarely needs replacement and blows usually as a result of the operator’s error.
Open the case as mentioned above and take the PCB assembly out from the case.
Replace the blown fuse with ratings specified.
F1 : F 300mA/250V F2 : F 10A/250V
Remark :
Before attempting to open the case, be sure that test leads have been disconnected
from measurement circuit to avoid electric shock.