Mastech MS8201H Operator's Manual

DIGITAL MULTIMETER

OPERATOR’S MANUAL

CONTENTS

1. SAFETY INFORMATION ……1

1.1 PRELIMINARY ……1

1.2 DURING USE ……2

1.3 SYMBOLS ……5

1.4 MAINTENANCE ……6

2. DESCRIPTION ……8

2.1 NAMES OF COMPONENTS ……8

2.2

SWITCH AND BUTTONS
ELUCIDATE

……10

3. SPECIFICAT IONS ……11

3.1 GENERAL SPECIFICATIONS ……11

3.2

ELECTRICAL
SPECIFICATIONS

……12

4. OPERAT ING INSTRUCTION ……20

4.1 READ HOLD ……20

4.2 BACK LIGHT ……20

4.3 DC/AC TRANSFORM ……21

4.4 L/C TRANSFORM ……21

4.5

PREPARATION FOR
MEASUREMENT

……22

4.6 MEASURING DC VOLTAGE ……23

4.7 MEASURING AC VOLTAGE ……25

4.8 MEASURING DC CURRENT ……26

4.9 MEASURING AC CURRENT ……29

4.10 MEASURING RESISTANCE ……31

4.11 MEASURING CAPACITANCE ……33

4.12 MEASURING INDUCTANCE ……35

4.13

MEASURING
TEMPERATURE

……37

4.14 MEASURING FREQUENCY ……39

4.15 DIODE TESTING ……40

4.16 CONTINUITY TESTING ……42

4.17 TRANSISTOR TESTING ……44

4.18 TTL LOGIC TESTING ……46

5.

MAINTENANCE

……49

5.1 BATTERY REPLACEMENT ……49

5.2 FUSE REPLACEMENT ……51

5.3

TEST LEADS
REPLACEMENT

……52

6. ACCESSORIES ……53

1. SAFETY INFORMATION
WARNING

To ensure safe operation, and in
order to exploit to the full the
functionality of the meter, please
follow the directions in this
section carefully.

This multimeter has been designed
according to IEC-1010 concerning
electronic measuring instruments with
an overvoltage category (CAT ΙΙ) and
pollution 2.

Follow all safety and operating
instructions to ensure that the meter is
used safely and is kept in good
operating condition.

With proper use and care, your digital
multimeter will give you years of
satisfactory service.

1.1 PRELIMINARY

1.1.1 When using the meter, the user

must observe all normal safety rules
concerning:

• Protection against the dangers of
electrical current.

Digital Multimeter 1

• Protection of the meter against
misuse.

1.1.2 When the meter is delivered,
check that it has not been damaged
in transit.

1.1.3 When poor condition under harsh
preservation or shipping conditions
caused, inspect and confirm this
meter without delay.

1.1.4 Measuring leads must be in good
condition. Before using verify that
the insulation on test leads is not
damaged and/or the leads wire is
not exposed.

1.1.5 Full compliance with safety
standards can be guaranteed only if
used with test leads supplied. If
necessary, they must be replaced
with the same model or same
electric ratings.

1.2 DURING USE

1.2.1 Before using, you must select the
right input jack, function and range.

1.2.2 Never exceed the protection limit
values indicated in specifications for

2 Digital Multimeter

each range of measurement.

1.2.3 When the meter is linked to a
measurement circuit, do not touch
unused terminals.

1.2.4 When the value scale to be
measured is unknown beforehand,
set the range selector at the highest
position.

1.2.5 Do not measure voltage if the
voltage on the terminals exceeds
1000V above earth ground.

1.2.6 Always be careful when working
with voltages above 60V DC or 30V
AC rms, keep fingers behind the
probe barriers while measuring.

1.2.7 Never connect the meter leads
across a voltage source while the
function switch is in the current,
resistance, capacitance, inductance,
temperature, frequency, diode,
transistor or continuity mode. Doing
so can damage the meter.

1.2.8 Before rotating the range switch
to change functions and ranges,
disconnect test leads from the

Digital Multimeter 3

circuit under test.

1.2.9 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.

1.2.10 Never perform resistance,
capacitance, inductance, diode and
continuity measurements on live
circuits.

1.2.11 Never perform capacitance
measurements unless the capacitor
to be measured has been
discharged fully.

1.2.12 Never use the meter under the
condition of the explosive air, steam
or dirt.

1.2.13 If any faults or abnormalities are
observed, the meter can not be
used any more and it has to be
checked out.

1.2.14 Never use the meter unless the
rear case is in place and fastened
fully.

4 Digital Multimeter

1.2.15 Please do not store or use
meter in areas exposed to direct
sunlight, high temperature, humidity
or condensation.

1.3 SYMBOLS

Important safety information, refer

to the operating manual.

Double insulation （ Protection

classΙΙ）.

CAD II Overvoltage (Installation)

category II, Pollution Degree 2
per IEC1010-1 refers to the
level of Impulse Withstand
Voltage protection provided.

CAT III Overvoltage (Installation)

category III, Pollution Degree 2
per IEC1010-1 refers to the
level of Impulse Withstand
Voltage protection provided.

Conforms to European Union

Directive

Earth ground

Power ON/OFF

Fuse

Low Battery

Digital Multimeter 5

~ AC (alternating current)

DC (direct current)

Continuity Buzzer

~ AC or DC (alternating current or

direct current)

1.4 MAINTENANCE

1.4.1 Please do not attempt to adjust or
repair the meter by removing the
rear case while voltage is being
applied. A technician who fully
understands danger involved should
only carry out such actions.

1.4.2 Before opening the battery cover
or case of the meter, always
disconnect test leads from all tested
circuits.

1.4.3 To avoid the wrong reading
causing electricity attack, when the
meter displays “

”, you must

change the battery.

1.4.4 For continue protection against
fire, replace fuse only with the
specified voltage and current ratings:
F 250mA

/250V (quick acting,

≤1

6 Digital Multimeter

resistance

Ω

), F 12.5A / 250V

1.4.5 Do not use abrasives or solvents
on the meter, use a damp cloth and
mild detergent only.

1.4.6 Always set the power switch to
the OFF position when the meter is
not in use.

1.4.7 If the meter is to be stored for
a long period of time, the batteries
should be removed to prevent
damage to the unit.

Digital Multimeter 7

(quick acting).

2. DESCRIPTION

- This meter is a portable professional
measuring instrument with large
LCD and back light easily reading.

- Single operation of a range switch
makes measurement convenient.
Overload protection and low battery
indication are provided, this meter is
ideal for use in the fields, workshop,
school, hobby and home
applications.

- This meter has function of data hold.

- When using, it can show ranges
engineering unit enunciators
measuring results.

2.1 NAMES OF COMPONENTS

① LCD Display
② L/C Button
③ Power Button (

)

④ Range Switch

⑤

⑥ Battery cover
⑦ 10A Jack

8 Digital Multimeter

Top shell

⑧

COM jack

⑨

DC/AC Button（DC/AC）

⑩

Back Light Button (LIGHT)
Data Button(HOLD)

Digital Multimeter 9

, Ω, ℃, A, V, Hz, H Jack

11

12

2.2 SWITCH AND BUTTONS
ELUCIDATION

• Range Switch

This switch is used to select functions
and desired ranges.

• Power Button (

)

This Button is used to the switch of
power.

• L/C Button（L/C）

This Button is used to the capacitance
and inductance measurements. In this
range, press the button to begin the
measurement. The other ranges will
be loosened.

• Data Button (HOLD)

This Button is used to the switch of
data hold

• DC/AC Button（DC/AC）

This Button is used to the AC voltage
and AC current measurements. Once
press the button to the alternative
state, then the measurement begins.
The other ranges will be loosened.

• Back Light Button (LIGHT)

This Button is used to the switch of
back light.

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3. SPECIFICATIONS

Accuracy is specified for a period of
year after calibration and at 18℃ to 28
℃（64°F to 82°F） with relative humidity
to 75%.

3.1 GENERAL SPECIFICATIONS

3.1.1Measuring method: Dual-slope
integration A/D converter

3.1.2 Sampling Time: approx. 0.4
second

3.1.3 Display: 25mm LCD

3.1.4 Max. Show Value: 1999 (3 1/2)

3.1.5 Polarity Indication: ‘-’indicates
negative polarity.

3.1.6 Overrange Indication: Display ‘1’

3.1.7 Unit showing: showing of
electrical capacity.

3.1.8 Low Battery Indication: ‘

’

displayed

3.1.9 Operating Altitude: 2000 meters
(7000 ft.) maximum

3.1.10 Max. Voltage Between Terminals

And Earth Ground: 1000V DC or 700

3.1.11 Fuse Protection: F 250mA/250V

Digital Multimeter 11

AC rms.

(quick acting, resistance ≤1Ω), F

12.5A/250V (quick acting).

3.1.12 Power Supply: 9V battery, NEDA
1604 or 6F22

3.1.13 Operating Temperature: 0℃ to
40℃（32°F to 104°F）

3.1.14 Storage Temperature: -10℃ to
50℃（10°F to 122°F）

3.1.15 Dimension: 185×84×38 mm

3.1.16 Weight: approx. 300g（including
battery）

3.2 ELECTRICAL SPECIFICATIONS

Circumstance Temperature: 23±5 ℃
Relative Humidity: < 75%

3.2.1 DC Voltage

Range Resolution Accuracy

200mV 0.1mV ±（0.5% of rdg + 1 digit）

2V 1mV ±（0.5% of rdg + 3 digits）

20V 10mV ±（0.5% of rdg + 3 digits）

200V 100mV ±（0.5% of rdg + 3 digits）

1000V 1V ±（0.8% of rdg + 3 digits）

- Input Impedance: 10MΩ

- Overload Protection: 200mV range:

12 Digital Multimeter

250V DC or rms AC, 2V-1000V
ranges: 1000V DC or 700V rms AC.

- Max. Input Voltage: 1000V DC

NOTE:

At the little voltage range, the meter will
show unsteady reading when test leads
haven’t reach the circuit, it’s normal
because the meter is very sensitivity.
When test leads touch the circuit, you
can get the true reading.

3.2.2 AC Voltage

Range Resolution Accuracy

200mV 0.1mV ±（1.2% of rdg + 5 digits）

2V 1mV ±（1.0% of rdg + 5 digits）

20V 10mV ±（1.0% of rdg + 5 digits）
200V 100mV ±（1.0% of rdg + 5 digits）
700V 1V ±（1.2% of rdg + 3 digits）

- Input Impedance: 10MΩ

- Overload Protection: 200mV range:
250V DC or rms AC, 2V-700V ranges:
1000V DC or 700V rms AC.

- Frequency Range: 40 to 400Hz

- Response: Average, calibrated in

Digital Multimeter 13

rms of sine wave.

- Max. Input Voltage: 700V rms AC

NOTE:

At the little voltage range, the meter will
show unsteady reading when test leads
haven’t reach the circuit, it’s normal
because the meter is very sensitivity.
When test leads touch the circuit, you
can get the true reading.

3.2.3 DC Current

Range Resolution Accuracy

2mA 1μA ±（1.0% of rdg + 3 digits）

20mA 10μA ±（1.0% of rdg + 3 digits）

200mA 100μA ±（1.5% of rdg + 5 digits）

10A 10mA ±（2.0% of rdg + 10 digits）

- Overload Protection: 2 to 200mA
ranges: F1: F 250mA/250V fuse
(quick acting, resistance ≤1Ω), 10A
range: F2: F 12.5A/250V fuse (quick
acting).

- Max. Input Current: mA Jack: 200mA,
10A Jack: 10A

- Voltage Drop: 200mV

14 Digital Multimeter

3.2.4 AC Current

Range Resolution Accuracy

2mA 1μA ±（1.2% of rdg + 5 digits）

20mA 10μA ±（1.2% of rdg + 5 digits）

200mA 100μA ±（2.0% of rdg + 5 digits）

10A 10mA ±（3.0% of rdg + 10 digits）

- Overload Protection: 2 to 200mA
ranges: F1: F 250mA/250V
fuse(quick acting, resistance ≤1Ω)，
10A range: F2: F 12.5A/250V fuse
(quick acting).

- Max. Input Current: mA Jack: 200mA,
10A Jack: 10A

- Voltage Drop: 200mV

- Frequency Range: 40 to 400Hz

- Response: Average, calibrated in
rms of sine wave

3.2.5 Resistance

Range Resolution Accuracy

200Ω 0.1Ω ±（1.0% of rdg + 3 digits）

2kΩ 1Ω ±（1.0% of rdg + 1 digit）

20kΩ 10Ω ±（1.0% of rdg + 1 digit）

Digital Multimeter 15

200kΩ 100Ω ±（1.0% of rdg + 1 digit）

2MΩ 1kΩ ±（1.0% of rdg + 1 digit）

20MΩ 10kΩ ±（1.0% of rdg + 5 digits）

- Open Circuit Voltage: approx.
700mV

- Overload Protection: 250V DC or

rms AC

3.2.6 Capacitance

Range Resolution Accuracy

2nF 1pF ±（4% of rdg + 8 digits）

20nF 10pF ±（4% of rdg + 3 digits）

200nF 0.1nF ±（4% of rdg + 3 digits）

2μF 1nF ±（4% of rdg + 3 digits）

20μF 10nF ±（4% of rdg + 5 digits）

- Overload Protection: F1: F
250mA/250V fuse(quick acting,
resistance ≤1Ω)

3.2.7 Inductance

Range Resolution Accuracy

2mH 0.001mH ±（4% of rdg + 8 digits）

20mH 0.01mH ±（4% of rdg + 3 digits）

16 Digital Multimeter

200mH 0.1mH ±（4% of rdg + 3 digits）

2H 1mH ±（4% of rdg + 3 digits）

20H 10mH ±（4% of rdg + 5 digits）

- Overload Protection: F1: F
250mA/250V fuse(quick acting,
resistance ≤1Ω)

- Tested Inductance: Q≥10，Internal

impedance≤1kΩ

-

3.2.8 Temperature

Range -20℃ to 1000℃

Resolution 1℃

-20℃ to 0℃ ±（5% of rdg + 4digits）

Accuracy 0℃ to 400℃ ±（1% of rdg + 3digits）

400℃ to 1000℃ ±（2% of rdg + 3digits）

- Overload Protection: F1: F
250mA/250V fuse (quick acting,
resistance ≤1Ω)

3.2.9 Frequency

Range Resolution Accuracy

20kHz 10Hz ±（1.5% of rdg + 5 digits）

- Sensitivity: 200mV rms and input no

Digital Multimeter 17

more 10V rms

- Overload Protection: 250V rms AC

3.2.10 Transistor hFE

Range Function

hFE

Display: read approximate hFE value
(0-1000) of transistor under test (ALL
TYPE)

- Base Current: approx. 10μA，Vce:
approx. 2.8V

- Overload Protection: F1: F
250mA/250V fuse (quick acting,
resistance ≤1Ω)

-

3.2.11 Diode

Range Resolution Function

1mV

Display :read approximate
forward voltage of diode

- Forward DC Current: approx. 1mA

- Reversed DC Voltage: approx.2.8V

- Overload Protection:

250V DC or rms

AC

18 Digital Multimeter

3.2.12 Continuity

Range Function

Built-in buzzer will sound, if
resistance is lower than 50Ω.

- Open circuit voltage: approx. 2.8V

- Overload Protection: 250V DC or
rms AC

3.2.13 TTL Logic

Range Function

When logic level is less or on

0.8V, LCD displays “

” and the
buzzer produces sound. When
logic level is more and on 2.0V,
LCD displays “

”.

Digital Multimeter 19

4. OPERATING INSTRUCTION

4.1 READ HOLD

If you need data hold when measuring,
you can put on “HOLD” button, it will
hold the reading; if you put the button
again, data hold is not continue.

4.2 BACK LIGHT

If the light is dark to make the reading
difficult when measuring, you can put
on “LIGHT” button to open the back
light.

NOTE:

• LED is the main source of back light.
Its working current is large, although
the meter has the timer equipment
(time is 5 seconds and it will off
automatically after 5 seconds); often
use back light will shorten the battery
life, you’d better not to use the back
light so frequently if it’s not
necessary.

• When the battery voltage is less than
7V, it will show “

”. But if you use
back light at the same time, maybe
“ ” will come up even if the battery

20 Digital Multimeter

voltage is more than 7V, because the
working current is higher and the
voltage will decline. (When
“

“ shows, the accuracy of the
measurement can not be assured.)
You need not replace the battery.
When you use normally (back light is
not using), “ ” will not show up. You
need replace it till “

”show again.

4.3 DC/AC transform

Put down the "DC/AC" button when
measuring the voltage. Meter will be
transformed to the AC measuring state.

NOTE:

• Except the AC voltage and AC

current ranges, you ought to loosen
DC/AC button.

4.4 L/C transform

Put down the "L/C" button when
measuring the capacitance and
inductance. Then the meter can be
tested.

NOTE:

• Except the capacitance and

inductance ranges, the L/C button

Digital Multimeter 21

should be loosened.

4.5

PREPARATION FOR

MEASUREMENT

4.5.1 Put on the “

” button. If the
battery voltage is less than 7V,
display will show “

”, the battery

should be changed at this time.

4.5.2 The “

” besides the input jack
shows that the input voltage or
current should be less than
specification on the sticker of the
meter to protect the inner circuit
from damaging.

4.5.3 Select a function and a range for
the item to be measured through
rotating the range switch
accordingly. When the value scale
to be measured is unknown
beforehand, set the range selector
at the highest position.

4.5.4 When connection, first connect to
the public testing line, then to the
electriferous testing line. When
you’ll remove it, you should remove
the elecriferous one.

22 Digital Multimeter

4.6 MEASURING DC VOLTAGE

WARNING

You can’t input the voltage which
more than 1000V DC, it’s possible to
show higher voltage, but it’s may
destroy the inner circuit.

Pay attention not to get an electric
shock when measuring high voltage.

4.6.1 Connect the black test lead to the
COM jack and the red test lead to
the V jack.

4.6.2 Set the range switch at the
desired V range position.

4.6.3 Connect test leads across the
source or load under measurement.

4.6.4 You can get a reading from LCD
display. The polarity of the red lead
connection will be indicated along
with the voltage value.

NOTE:

• When only the figure ‘1’ is displayed,
it indicates overrange situation and
the higher range has to be selected.

• When the value scale to be

measured is unknown beforehand,

Digital Multimeter 23

set the range selector at the highest
position.

24 Digital Multimeter

4.7 MEASURING AC VOLTAGE
WARNING

You can’t input the voltage which
more than 700V rms AC, it’s possible
to show higher voltage, but it’s may
destroy the inner circuit.

Pay attention not to get an electric
shock when measuring high voltage.

4.7.1 Connect the black test lead to the

COM jack and the red test lead to
the V jack.

4.7.2 Set the range switch at the

desired V range position.

4.7.3 Put down the "DC/AC" button,

meter will be transformed to the AC
measuring state.

4.7.4 Connect test leads across the

source or load under measurement.

4.7.5 You can get reading from LCD.

NOTE:

• When only the figure ’1’ is displayed,
it indicates overrange situation and
the higher range has to be selected.

• When the value scale to be

Digital Multimeter 25

measured is unknown beforehand,
set the range selector at the highest
position.

4.8 MEASURING DC CURRENT
WARNING

Shut down the power of the tested
circuit, then connect the meter with
the circuit for measurement.

26 Digital Multimeter

4.8.1 Connect the black test lead to the

COM jack and the red test lead to
the A jack for a maximum of 200mA
current. For a maximum of 10A,
move the red lead to the 10A jack.

4.8.2 Set the range switch at the

desired A

range position.

4.8.3 Connect test leads in series with

the load under measurement.

4.8.4 You can get reading from LCD.

The polarity of red connection will
be indicated along with the voltage
value.

NOTE:

• When only the figure ‘1’ is displayed,
it indicates overrange situation and
the higher range has to be selected.

• When the value scale to be
measured is unknown beforehand,
set the range selector at the highest
position.

Digital Multimeter 27

• “ ” means the maximum current of
A socket is 250mA, the maximum
current of 10A socket is 12.5A,
over-current will destroy the fuse.

28 Digital Multimeter

4.9 MEASURING AC CURRENT
WARNING

Shut down the power of the tested
circuit, then connect the meter with
the circuit for measurement.

4.9.1 Connect the black test lead to the

COM jack and the red test lead to
the A jack for a maximum of 200mA
current. For a maximum of 10A,
move the red lead to the 10A jack.

4.9.2 Set the range switch at the

desired A

range position.

4.9.3 Put down the "DC/AC" button,

meter will be transformed to the AC
measuring state.

4.9.4 Connect test leads in series with

the load under measurement.

4.9.5 You can get reading from LCD.

NOTE:

• When only the figure ‘1’ is displayed,
it indicates overrange situation and
the higher range has to be selected.

• When the value scale to be
measured is unknown beforehand,
set the range selector at the highest
position.

Digital Multimeter 29

• “ ” means the maximum current
of A socket is 250mA, the maximum
current of 10A socket is 12.5A,
over-current will destroy the fuse.

30 Digital Multimeter

4.10 MEASURING RESISTANCE
WARNING

When measuring in-circuit
resistance, be sure the circuit under
test has all power removed and that
all capacitors have been discharged
fully.

4.10.1 Connect the black test lead to

the COM jack and the red test
lead to the Ω jack.

4.10.2 Set the range switch at the

desired Ω range position.

4.10.3 Connect test leads across the

resistance under measurement.

4.10.4 You can get reading from LCD.

NOTE:

• When only the figure ‘1’ is displayed,
it indicates overrange situation and
the higher range has to be selected.

• For measuring resistance above
1MΩ, the meter may take a few
seconds to get stable reading.

• When the input is not connected, i.e.
at open circuit, the figure ‘1’ will be
displayed for the overrange
condition.

Digital Multimeter 31

32 Digital Multimeter

4.11 MEASURING CAPA CITANCE
WARNING

To avoid electrical shock, remove
test leads from measurement circuits
before measuring the capacitance of
a capacitor.

To avoid electric shock, be sure the
capacitors have been discharged
fully before inserting capacitors
under measurement into
multifunction testing socket.

4.11.1 Connect the black test lead to

the COM jack and the red test lead
to the

jack.

4.11.2 Set the range switch at the

desired F range position and press
“L/C” button down.

4.11.3 Before connect test leads across

two sides of the capacitor under
measurement, be sure that the
capacitor has been discharged fully.

4.11.4 You can get readin g from LCD.

4.11.5 When frequent capacitance

testing

Digital Multimeter 33

is needed, put the plug of
multifunction testing equipment
(spare parts) into COM jack and

34 Digital Multimeter

jack, also put the capacitor feet into
two long sockets of multifunction
testing equipment, then the
capacitance testing is ready.

NOTE:

• At the small capacitor range, the
reading will include the small value
because some influence from the
distribution of test leads. It will not
influence the accuracy of measuring.

• It takes time to steady the reading
when measuring high capacity.

4.12 MEASURING INDUCTANCE

4.12.1 Connect the black test lead to
the COM jack and the red test lead
to the H jack.

4.12.2 Set the range switch at the
desired H range position and press
“L/C” button down.

4.12.3 Connect test leads across two
sides of the inductor under
measurement.

Digital Multimeter 35

4.12.4 You can get reading from LCD.

4.12.5 When frequent inductance
testing is needed, put the plug of
multifunction testing equipment
(spare parts) into COM jack and H
jack, and put the inductor feet into

36 Digital Multimeter

two long sockets of multifunction
testing equipment, then the
inductance testing is ready.

NOTE:

• Inductance test shall be stay away
from any strong magnetic field to
ensure an accurate measurement.

4.13 MEASURING TEMPERATURE
WARNING

To avoid electrical shock, do not
connect the thermocouples with the
electriferous circuit.

4.13.1 Set the range switch at the ℃

range position.

4.13.2 The ‘LCD’ display will show the

current environment temperature.

4.13.3 Insert ‘K’ type thermocouples

into the COM jack and ℃ jack (or
you can

Digital Multimeter 37

insert it by using multifunction
testing equiqment)， then connect
the object with the thermocouple
probe for measurement.

4.13.4 You can get reading from LCD.

38 Digital Multimeter

4.14 MEASURING FREQUENCY

4.14.1 Connect the black test lead to

the COM jack and the red test lead
to the Hz jack.

4.14.2 Set the range switch at the

20kHz range position.

4.14.3 Connect test leads across the

source or load under measurement.

4.14.4 You can get reading from LCD.

NOTE:

• Reading is possible at input voltages
above 10Vrms, but the accuracy is
not guaranteed.

• In noisy environment, it is preferable
to use shield cable for measuring
small signal.

Digital Multimeter 39

4.15 TESTING DIODE

4.15.1 Connect the black test lead to
the COM jack and the red test lead
to the V jack. (The polarity of red

40 Digital Multimeter

lead is “+”)

4.15.2 Set the range switch at the
range position.

4.15.3 Connect the red lead to the
anode, the black lead to the
cathode of the diode under testing.

4.15.4 You can get reading from LCD.

NOTE:

• The meter will show the approximate
forward voltage drop of the diode.

• If the lead connection is reversed,
only figure‘1’will be displayed.

• When the input is not connected, i.e.
at open circuit, the figure ‘1’ will be
displayed.

Digital Multimeter 41

4.16 CONTINUITY TEST
WARNING

When testing the circuit continuity,
be sure that the power of the circuit
has been shut down and all
capacitors have been discharged
fully.

42 Digital Multimeter

4.16.1 Connect the black test lead to

the COM jack and the red test lead
to the Ω jack.

4.16.2 Set the range switch at the

range position.

4.16.3 Connect test leads across two

points of the circuit under testing.

4.16.4 If continuity exists （ i.e.,

resistance less than about 50Ω）,
built-in buzzer will sound.

NOTE:

• If the input open circuit, the figure

‘1’ will be displayed.

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4.17 TESTING TRANSISTOR

4.17.1 Set the rotary switch at the hFE

range position.

4.17.2 Put two plugs of multifunction

testing equipment (spare parts) into

44 Digital Multimeter

COM jack and V jack.

4.17.3 Identify whether the transistor is

NPN or PNP type and insert emitter,
base and collector leads into the
proper holes of the transistor on the
multifunction testing equipment
(spare parts) for testing.

4.17.4 You can get reading from LCD.

Digital Multimeter 45

4.18 TTL LOGIC TEST

4.18.1 Connect the black test lead to

the COM jack and the red test lead
to the V jack.

46 Digital Multimeter

4.18.2 Set the range switch at the

range position.

4.18.3 Connect test leads across two

sides of the circuit under testing.

4.18.4 When logic level is less or on

0.8V, LCD displays “

” and the
buzzer produces sound. When logic
level is more and on 2.0V, LCD
displays “

”.

Digital Multimeter 47

48 Digital Multimeter

5. MAINTENANCE

5.1 BATTERY REPLACEMENT
WARNING

Before attempting to remove the
battery cover or open the case, be
sure that test leads have been
disconnected from measurement
circuit to avoid electric shock hazard.

5.1.1 If the sign‘ ’appears on the

LCD display, it indicates that the
battery should be replaced.

5.1.2 Loosen the fixing screw of the

case and remove battery cover from
the front of the meter.

5.1.3 Replace the exhausted battery

with a new one.

5.1.4 Put the battery cover as its origin.

Digital Multimeter 49

Battery cover

9V Battery

Fig 15

50 Digital Multimeter

5.2 FUSE REPLACEMENT

WARNING

To avoid electrical shock, remove
test leads from measurement
circuits before replacing the fuse.

For protection against fire, replace
fuses only with specified ratings:
F1: F 250mA/250V (quick acting,
resistance ≤1Ω)，

F2: F 12.5A/250V

(quick acting).

5.2.1 Fuse rarely need replacement

and blow almost always as a result
of the operator’s error.

5.2.2 Loosen the fixing screw of the

case and remove it.

5.2.3 Replace the blown fuse with

ratings specified.

5.2.4 Put the case as its origin.

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5.3 TEST LEADS REPLACEMENT

WARNING

Full in compliance with safety
standards can be guaranteed only if
used with test leads supplied. If
necessary, they must be replaced
with the same model or same electric
ratings. Electric ratings of the test
leads: 1000V 10A.

You must be replaced the test leads if
the lead is exposed.

52 Digital Multimeter

6. ACCESSORIES

c

Test Leads: Electric Ratings 1000V 1 0A one piece

d

Battery: 9V, NEDA 1604 or 6F22 one piece

e

Operating Manual one piece

f

Holster one piece

g

Thermocouple (K type) one piece

h

Multifunction test socket one piece

Digital Multimeter 53