GW Instek GDM-356 User manual

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GDM-356
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Table of Contents
Title
Overview
Unpacking Inspection
Safety Information
Rules For Safe Operation
International Electrical Symbols
The multimeter Structure
Functional Buttons
Display Symbols
Measurement Operation
A. DC Voltage Measurement
B. AC Voltage Measurement
C. DC Current Measurement
D. AC Current Measurement
E. Measuring Resistance
F. Frequency Measurement
G. Temperature Measurement
H. Capacitance Measurement
I. Measuring Diodes & Continuity
General Specifications
Testing for Continuity
Sleep Mode
Turning on theAuto Display Backlight
Accuracy Specifications
A. DC Voltage
B. AC Voltage
C. DC Current
D. AC Current

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I. Diodes and Continuity Test 30
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C. Replacing the Fuses
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Title
E. Resistance Test
F. Frequency
G. Temperature
H. Capacitance
Maintenance
A. General Service
B. Replacing the Battery

Overview
Warning
To avoid electric shock or personal injury, read the
"Safety Information" and "Rules for Safe Operation"
carefully before using the Meter.
Digital Multimeters Model GDM-356 (hereafter referred
to as “the Meter”) are 3 1/2 digits with steady operations,
fashionable structure and highly reliable hand-held
measuring instrument. The Meter uses large scale of
integrated circuit with double integrated A/D converter
as its core and has full range overload protection. The
Meter not only can measure AC/DC Voltage, AC/DC
Current, Resistance, Capacitance, Temperature,
Frequency, Diodes and Continuity, but also has Data
Hold, Full Icon Display and Sleep Mode features.
The Meter adopted advanced “co-injection” technique in
order to provide sufficient insulation and anti-shaking.
In addition, the Automatic Display Backlight feature
enables user to work in a dim condition.
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Unpacking Inspection
Open the package case and take out the Meter. Check
the following items carefully to see any missing or
damaged part:
In the event you find any missing or damage, please
contact your dealer immediately.
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Item
1
2
3
4
Description
English Operating Manual
Test Lead
Test Clip
Point Contact Temperature Probe
Qty
1 piece
1 pair
1 pair
1 piece

Safety Information
This Meter complies with the standards IEC61010: in
pollution degree 2, overvoltage category (CAT. II 1000V,
CAT. III 600V) and double insulation.
CAT. II: Local level, appliance, PORTABLE EQUIPMENT
etc., with smaller transient voltage overvoltages than
CAT. III
CAT. III: Distribution level, fixed installation, with smaller
transient overvoltages than CAT. IV
Use the Meter only as specified in this operating manual,
otherwise the protection provided by the Meter may be
impaired.
In this manual, a Warning identifies conditions and
actions that pose hazards to the user, or may damage
the Meter or the equipment under test.
A Note identifies the information that user should pay
attention on.
International electrical symbols used on the Meter and
in this Operating Manual are explained on page 8.
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Rules For Safe Operation (1)
Warning
To avoid possible electric shock or personal injury,
and to avoid possible damage to the Meter or to the
equipment under test, adhere to the following rules:
l Before using the Meter inspect the case. Do
not use the Meter if it is damaged or the case
(or part of the case) is removed. Look for cracks
or missing plastic. Pay attention to the insulation
around the connectors.
l Inspect the test leads for damaged insulation
or exposed metal. Check the test leads for
continuity. Replace damaged test leads with
identical model number or electrical specifications
before using the Meter.
l Do not apply more than the rated voltage, as
marked on the Meter, between the terminals or
between any terminal and grounding.
l The rotary switch should be placed in the right
position and no any changeover of range shall
be made during measurement is conducted to
prevent damage of the Meter.
l When the Meter working at an effective voltage
over 60V in DC or 30V rms in AC, special care
should be taken for there is danger of electric
shock.
l Use the proper terminals, function, and range
for your measurements.
l Do not use or store the Meter in an environment
of high temperature, humidity, explosive,
inflammable and strong magnetic field. The
performance of the Meter may deteriorate after
dampened.
l When using the test leads, keep your fingers
behind the finger guards.
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Rules For Safe Operation (2)
l Disconnect circuit power and discharge all high-
voltage capacitors before testing resistance,
continuity, diodes, capacitance or current.
l Before measuring current, check the Meter’s
fuses and turn off power to the circuit before
connecting the Meter to the circuit.
l Replace the battery as soon as the battery
indicator appears. With a low battery, the Meter
might produce false readings that can lead to
electric shock and personal injury.
l Remove test leads, test clips and temperature
probe from the Meter and turn the Meter power
off before opening the Meter case.
l When servicing the Meter, use only the same
model number or identical electrical specifications
replacement parts.
l The internal circuit of the Meter shall not be
altered at will to avoid damage of the Meter and
any accident.
l Soft cloth and mild detergent should be used
to clean the surface of the Meter when servicing.
No abrasive and solvent should be used to
prevent the surface of the Meter from corrosion,
damage and accident.
l The Meter is suitable for indoor use.
l Turn the Meter power off when it is not in use
and take out the battery when not using for a
long time.
l Constantly check the battery as it may leak when
it has been using for some time, replace the
battery as soon as leaking appears. A leaking
battery will damage the Meter.
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International Electrical Symbols
AC (Alternating Current).
DC (Direct Current).
AC or DC.
Grounding.
Double Insulated.
Deficiency of Built-In Battery.
Continuity Test.
Diode.
Capacitance Test.
Fuse.
Warning. Refer to the Operating Manual.
Conforms to Standards of European Union.
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The multimeter Structure (see figure 1)
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( figure 1)
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Functional Buttons
Below table indicated for information about the functional
button operations
Button Operation Performed
HOLD
(Blue Button)
POWER
(Yellow Button)
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Display Symbols (see figure 2)
( figure 2)
No. Symbol Meaning
1Dangerous Voltages.
2The battery is low.
Warning:To avoid false readings,
which could lead to possible electric
shock or personal injury, replace the
battery as soon as the battery
indicator appears.
3Indicator for AC voltage or
current.The displayed value is the
mean value.
4Indicates negative reading.
5Test of diode.
6Data hold is active.
7The continuity buzzer is on.
8Centigrade temperature
oC
oF
9Fahrenheit temperature
µA, mA, A A: Amperes (amps). The unit of
current.
mA: Milliamp. 1 x 10-3 or 0.001
amperes.
µA: Microamp. 1x 10-6 or 0.000001
amperes.
10
V: Volts. The unit of voltage.
mV: Millivolt. 1 x 10-3 or 0.001 volts.
mV, V
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Display Symbols (see figure 2)
No. Symbol Meaning
nF, µF
12 F: Farad. The unit of capacitance.
µF: Microfarad.1 x 10-6 or 0.000001
farads.
nF: Nanofarad.1 x 10-9 or0.000000001
farads.
kHz
13 The unit of frequency in cycles/
second. Kilohertz. 1 x 10-3 or
1,000 hertz.
Ω: Ohm. The unit of resistance.
kΩ: kilohm. 1 x 103or 1000
ohms.
MΩ: Megaohm. 1 x 106or 1,000,000
ohms.
Ω,kΩ,MΩ
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Measurement Operation(1)
A. DC Voltage Measurement (see figure 3)
Warning
To avoid harms to you or damages to the Meter from
electric shock, please do not attempt to measure
voltages higher than 1000V or 750V rms although
readings may be obtained.
The DC Voltage ranges are: 200mV, 2V, 20V, 200V and
1000V. To measure DC voltage, connect the Meter as
follows:
( figure 3)
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Measurement Operation(2)
Note
l If the value of voltage to be measured is unknown,
use the maximum measurement position (1000V)
and reduce the range step by step until a satisfactory
reading is obtained.
l The LCD displays "1"indicating the existing selected
range is overloaded, it is required to select a higher
range in order to obtain a correct reading.
l In each range, the Meter has an input impedance of
approx. 10MΩThis loading effect can cause
measurement errors in high impedance circuits. If the
circuit impedance is less than or equal to 10kΩ, the
error is negligible (0.1% or less).
l When DC voltage measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
B. AC Voltage Measurement (see figure 4)
Warning
To avoid harms to you or damages to the Meter from
electric shock, please do not attempt to measure
voltages higher than 1000V or 750V rms although
readings may be obtained.
( figure 4)
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TheAC voltage measurement has 4 measurement
positions on the rotary switch: 2V, 20V, 200V and 750V
To measure AC Voltage, connect the Meter as follows:
Measurement Operation(3)
1. Insert the red test lead into the VΩterminal and
the black test lead into the COM terminal.
2. Set the rotary switch to an appropriate measurement
position in V range.
3. Connect the test leads across with the object being
measured. The measured value shows on the display,
which is effective value of sine wave (mean value
response).
Note
l If the value of voltage to be measured is unknown,
use the maximum measurement position (750V) and
reduce the range step by step until a satisfactory
reading is obtained.
l The LCD displays "1"indicating the existing selected
range is overloaded, it is required to select a higher
range in order to obtain a correct reading.
l In each range, the Meter has an input impedance of
approx. 10MΩThis loading effect can cause
measurement errors in high impedance circuits. If
the circuit impedance is less than or equal to 10kΩ,
the error is negligible (0.1% or less).
l WhenAC voltage measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
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Measurement Operation(4)
C. DC Current Measurement (see figure 5)
Warning
Never attempt an in-circuit current measurement
where the open circuit voltage between terminals
and ground is greater than 60V DC or 30V rms.
If the fuse burns out during measurement, the Meter
may be damaged or the operator himself may be hurt.
Use proper terminals, function, and range for the
measurement. When the testing leads are connected
to the current terminals, do not parallel them across
any circuit.
The DC current measurement has 3 measurement
positions on the rotary switch: 20mA, 200mA and 20A.
To measure current, do the following:
1. Turn off power to the circuit. Discharge all high-
voltage capacitors.
( figure 5)
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2. Insert the red test lead into the µAmA or 20A terminal and
the black test lead into the COM terminal.
3. Set the rotary switch to an appropriate measurement
position in Arange.
4. Break the current path to be tested. Connect the red
test lead to the more positive side of the break and
the black test lead to the more negative side of the
break.
5. Turn on power to the circuit. The measured value
shows on the display.
Measurement Operation(5)
Note
l If the value of current to be measured is unknown,
use the maximum measurement position (20A) and
20A terminal, and reduce the range step by step until
a satisfactory reading is obtained.
l When current measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
D. AC Current Measurement (see figure 6)
( figure 6)
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red
black
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Measurement Operation(6)
Warning
Never attempt an in-circuit current measurement
where the voltage between terminals and ground is
greater than 60V.
If the fuse burns out during measurement, the Meter
may be damaged or the operator himself may be hurt.
Use proper terminals, function, and range for the
measurement. When the testing leads are connected
to the current terminals, do not parallel them across
any circuit.
TheAC current measurement has 3 measurement
positions on the rotary switch: 20mA, 200mA and 20A.
Note
l If the value of current to be measured is unknown,
use the maximum measurement position (20A) and
20A terminal and reduce the range step by step until
a satisfactory reading is obtained.
l When current measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
To measure current, do the following:
1. Turn off power to the circuit.Discharge all high-voltage
capacitors.
2. Insert the red test lead into the mA or 20A terminal
and the black test lead into the COM terminal.
3. Set the rotary switch to an appropriate measurement
position in Arange.
4. Break the current path to be tested. Connect the red
test lead to the more positive side of the break and
the black test lead to the more negative side of the
break.
5. Turn on power to the circuit.
The measured value shows on the display.
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E. Measuring Resistance (see figure 7)
Warning
To avoid damages to the Meter or to the devices under
test, disconnect circuit power and discharge all the
high-voltage capacitors before measuring resistance.
The resistance ranges are:
200Ω, 2kΩ, 20kΩ, 200kΩ, 2MΩ and 200MΩ.
To measure resistance, connect the Meter as follows:
1. Insert the red test lead into the VΩterminal and
the black test lead into the COM terminal.
2. Set the rotary switch to an appropriate measurement
position inΩrange.
3. Connect the test leads across with the object being
measured.The measured value shows on the display.
Note
l The test leads can add 0.1Ωto 0.3Ωof error to the
resistance measurement.To obtain precision readings
in low-resistance, that is the range of 200Ω, short-
circuit the input terminals beforehand and record the
reading obtained (called this reading as X). (X) is
the additional resistance from the test lead.
Then use the equation:
Measurement Operation(7)
( figure 7)
red black
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measured resistance value (Y) – (X) = precision
readings of resistance.
l For high resistance (>1MΩ), it is normal
taking several seconds to obtain a stable reading.
l When there is no input, for example in open circuit
condition, the Meter displays “1”.
l When resistance measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
Measurement Operation(8)
F. Frequency Measurement (see figure 8)
Warning
To avoid harm to you or damages to the Meter, do
not attempt to measure voltages higher than 60V in
DC or 30V rms in AC although readings may be
obtained. When the frequency signal to be tested is
higher than 30V rms, the Meter cannot guarantee
accuracy of the measurement.
( figure 8)
red black
The frequency measurement ranges are 2kHz and 20kHz.
To measure frequency, connect the Meter as follows:
1. Insert the red test lead into the VΩ terminal and
the black test lead into the COM terminal.
2. Set the rotary switch to an appropriate measurement
position in kHz range.
3. Connect the test leads across with the object being
measured.
The measured value shows on the display.
GDM-356