Mastech MS8228 User manual

MS8228
OPERATION MANUAL
DIGITAL MULTIMETER
hFE
mA
A
μA
mV
Hz
Duty
TEMP
FUSED,10A MAX
RESETTABLE
1000V
CAT III
AUTORANGE DMM
MS8228
/
hFE
IEC1010

43
43
41
41
41
Laser Beam......
10
4.11 Measuring Relative Humidity....................27
4.12
4.15 Measuring DC Millivoltage.......................31
4.16 Measuring AC Millivoltage.......................31
4.17 Measuring DC Current............................32
4.18 Measuring AC Current............................3 3
4.19 Measuring Frequency.............................3 4
4.20 Measuring Duty.......................................34
4.21 Measuring Resistance.............................35
4.22 Measuring Capacitance...........................36
4.23 Testing Diode...........................................36
4.24 Testing Continuity......................................37
4.25 Testing Transistor......................................38
4.26 Measuring Temperature
(With Infrared Thermo-Sensor)............40
27
26
4.13 Measuring DC Voltage............................27
4.14 Measuring AC Voltage............................27

’

N
TEMP&RRH
hFE
mA
A
μA
mV
Hz
Duty
TEMP
FUSED,10A MAX
RESETTABLE
1000V
CAT III
AUTORANGE DMM
MS8228
/
hFE
IEC1010
(

hFE
Infrared THERMO-Sensor
hFE
hFE.
hFE
Humidity Sensor
- for measuring humidity.
Infrared THERMO-Sensor
- for infrared temperature measuring
Laser Pointer
- for take aim object (infrared temperature measuring)
Laser Pointer

AUTO
RS232
AC( )
DC( )
hFE Transistor
Laser Pointer
IR-T Infrared Temperature
Emissivity
ε=0.95

40mV 0.01mV

40mV 0.01mV
(0.8% of reading + 3 digits)
(1.0% of reading + 3 digits)

Ω
Ω
Ω

- Max. input current:
V jack(mV ranges): 400mV
mA jack(μA ranges(: 4mA,
mA jack(mA ranges(: 400mA,
10A jack: 10A
- Overload Protection:
mV ranges: 250V DC or rms AC
A/mA ranges: resettable fuses F1 500mA/250V
10A range: F2 10A/250V fuse (quick acting).
μ

- By mV, µA, mA or A range:
Frequency response: 0 ~ 40kHz
Input current range: 1/4 of the rms AC for the range
(higher input voltage at higher frequency)
- Max. input current:
V jack(mV ranges): 400mV
mA jack(µA ranges): 4mA,
mA jack(mA ranges): 400mA,
10A jack: 10A
- Overload protection:
mV ranges: 250V DC or rms AC
µA/mA ranges: resettable fuses F1 500mA/250V
10A range: F2 10A/250V fuse (quick acting).
-20°C to 270°C
-270°C to 300°C
±(2.0%of reading + 3 digits)
±4.0% of reading
±(2.0%of reading + 6 digits)
°C
°F 1°F
1°C
-4 to 520°F °F
3.2.10.1 Temperature

3.2.13 Transistor hFE
Displaying approximate hFE value 1-1000
for transistor under test (ALL TYPE)
hFE
- Base current: ~10A,Vce: ~2V
- Overload protection: resettable fuses F1 500mA/250V.
hFE
4.1.4 At IR-T range, whether the test leads are plugged
in or otherwise, the meter will make no response
because no signal input is required from the
input terminals.

3) The back light will go off automatically after 10
seconds.

4.10.1 Switch on the power by turning the rotary selector.
If the battery voltage is lower than 3.6V, the “ ”
symbol will appear and the batteries should be
replaced.
4.10.2 The “ ” symbol beside the input lead shows
that the input voltage or current should not
exceed the specified value in order to protect
the internal circuit from damage.
4.10.3 Turn the rotary selector to the required function
and range to be measured. Under the manual
mode, choose the highest range when the value
scale to be measured is unknown.
4.10.4 Connect the common test lead first and then
the charged test lead when making connection.
Take away the charged test lead first when
disconnecting.
4.8 Laser Beam
Press the “ ” button for infrared temperature
measurement. A laser beam will be transmitted to
facilitate targeting at the object for more accurate result.
1) The laser pointer requires a larger working current.
Frequent use of laser beam will shorten the life of
the batteries. Therefore laser beam should not be
used unless necessary.
2) When the battery voltage is 3.6V, the symbol “ ”
(battery low)will appear on the LCD. When laser
beam is being used, even if the batter is 3.6V, the
“ ” may appear because of its large working
current which will cause the voltage to drop. (The
accuracy of the measurement cannot be assured
when the “ ” symbol appears.) In this case, you
need not replace the batteries yet. Normally, the
batteries can last until the “ ” appears when
laser beam is not being used.
:

4.11 Measuring Relative Humidity
4.11.1 This function is used for measuring the ambient
humidity around the meter.
4.11.2 Turn the rotary selector away from the OFF
position.
4.11.3 The current ambient humidity will be shown on
the humidity display of the LCD.
1) The humidity sensor is placed inside the front part
of the meter and therefore it may take a longer
time to reach balance with the environment being
measured. Furthermore, it takes a longer
intermission time, about 20 seconds, for sampling
and the meter has to be exposed to the environment
for a longer time for accurate reading. Hence it is
not suitable for measuring rapidly changing
ambient humidity.
2) It will take some time for a steady RH reading when
the ambient humidity changes.
4.12 Measuring Temperature
(With Thermo-Resistor)
4.12.1 This function is used for measuring the
ambient temperature around the meter.
4.12.2 Turn the rotary selector away from the OFF
position.
4.12.3 The current ambient temperature will be shown
on the temperature indicator of the LCD.
4.12.4 Press the “°C/°F" button to switch between
°C and °F measurement.
1) The temperature sensor (thermo-resistor) is placed
inside the front part of the meter and therefore it may
take a longer time to reach thermal balance with the
environment. Furthermore, it takes a longer
intermission time, about 20 seconds, for sampling
and the meter has to be exposed to the environment
for a longer time for accurate reading. Hence it is
not suitable for measuring rapidly changing ambient
temperature.
2) The working temperature of the meter is 0 ~ 40 °C.
As the temperature sensor is placed inside the meter,
this function is applicable for measuring ambient
temperature between 0 and 40°C.
3) If exposed to an environment beyond 0 ~ 40 °C ider
range of temperature measurement, but the
accuracy cannot be ensured and damage to the
meter may be caused.
4.13 Measuring DC Voltage
Beware of electrocution.
Pay special attention to avoid electric shock
when measuring high voltage.
Do not input any voltage over 1000V DC,
which may destroy the internal circuit,
although a higher voltage can be shown.
4.13.1 Plug the black test lead into the COM jack and
the red test lead into the V jack.
4.13.2 Set the rotary selector to the V range position.

4.13.3 Press the "SELECT" button to switch to DC
measurement. Then press the “RANGE” button
to choose the auto range or manual range mode.
4.13.4 Connect the test leads to the voltage source or
load for measurement.
4.13.5 Take the reading on the main indicator of the LCD.
The polarity symbol denotes the polarity of the
end connected by the red test lead.
1) At small voltage range, unsteady readings will
appear before the test leads contact the circuit.
This is normal because the meter is highly sensitive.
When the test leads contact the circuit, the true
reading will be shown.
2) Under the manual range mode, when only 'OL' or
'-OL' is shown on the LCD, it means the
measurement has exceeded the range. A higher
range should be selected.
3) Under the manual range mode, when the scale of the
value to be measured is unknown beforehand,
select the highest range first and lower the range
gradually.
4.14 Measuring AC Voltage
Beware of Electrocution.
Pay special attention to avoid electric shock
when measuring high voltage.
Do not input any voltage 750V rms AC, which
may destroy the inner circuit, although a
higher voltage can be shown.
4.14.1 Plug the black test lead into the COM jack and
the red test lead into the V jack.
4.14.2 Set the rotary selector to the V range position.
4.14.3 Press the "SELECT" button to switch to AC
measurement. Then press the “RANGE” button
to choose the auto range or manual range mode.
4.14.4 Connect the test leads to the voltage source or
load terminals for measurement.
4.14.5 Take the reading on the main indicator of the LCD.
1) At small voltage range, unsteady readings will
appear before the test leads contact the circuit.
This is normal because the meter is highly sensitive.
When the test leads contact the circuit, the true
reading will be shown.
2) Under the manual range mode, when only 'OL' or
'-OL' is shown on the LCD, it means the
measurement has exceeded the range. A higher
range should be selected.
3) Under the manual range mode, when the scale of the
value to be measured is unknown beforehand,
select the highest range first and lower the range
gradually.

4.15 Measuring DC Millivoltage
4.15.1 Plug the black test lead into the COM jack and
the red test lead into the V jack.
4.15.2 Set the rotary selector to the mV range position.
4.15.3 Press the "SELECT" button to switch to DC
measurement. Then press the “RANGE” button
to choose the auto range or manual range mode.
4.15.4 Connect the test leads to the voltage source or
load terminals for measurement.
4.15.5 Take the reading on the main indicator of the LCD.
The polarity symbol denotes the polarity of the end
1) When the input is open, unsteady readings may
appear. This is normal because the meter is highly
sensitive. When the test leads contact the circuit,
the true reading will be shown.
2) At the manual range mode, when only 'OL' or '-OL' is
shown on the LCD, it means the measurement has
exceeded the range. A higher range should be selected.
3) At the manual range mode, when the scale of the
value to be measured is unknown beforehand, set
the rotary selector to the highest range.
4.16 Measuring AC Millivoltage
4.16.1 Plug the black test lead into the COM jack and
the red test lead into the V jack.
4.16.2 Set the rotary selector to the mV range position.
4.16.3 Press the "SELECT" button to switch to AC
measurement. Then press the “RANGE” button
to choose the auto range or manual range mode.
4.16.4 Connect the test leads to the voltage source or
load terminals for measurement.
4.16.5 Take the reading on the main indicator of the LCD.
1) When the input is open, unsteady readings may
appear. This is normal because the meter is highly
sensitive. When the test leads contact the circuit,
the true reading will be shown.
2) At the manual range mode, when only 'OL' or '-OL' is
shown on the LCD, it means the measurement has
exceeded the range. A higher range should be selected.
3) At the manual range mode, when the scale of the
value to be measured is unknown beforehand, set
the rotary selector to the highest range.
4.17 Measuring DC Current
Beware of Electrocution.
Turn off the power of the circuit to be
measured before connecting the meter to
the circuit.
4.17.1 Plug the black test lead into the COM jack. When
the current to be measured is under 400mA,
plug the red test lead into the mA jack; when the
current to be measured is over 400mA but under
10A, plug the red test lead into the 10A jack.
4.17.2 Set the rotary selector to the A range position.
4.17.3 Press the "SELECT" button to switch to DC
measurement. Then press the “RANGE” button
to choose the auto range or manual range mode.
4.17.4 Connect the test leads to the circuit for
measurement.
4.17.5 Take the reading on the main indicator of the
LCD. The polarity symbol denotes the polarity
of the end connected by the red test lead.

1) At the manual range mode, when only 'OL' or '-OL' is
shown on the LCD, it means the measurement has
exceeded the range. A higher range should be
selected.
2) At the manual range mode, when the scale of the
value to be measured is unknown beforehand, set
the range to the highest.
3) “ ” means the maximum current of the mA jack is
400mA and the maximum current of the 10A jack is
10A. At the 10A jack, current exceeding the limit will
blow the fuse.
4.18 Measuring AC Current
Beware of Electrocution.
Turn off the power of the circuit to be
measured before connecting the meter to
the circuit.
4.18.1 Plug the black test lead into the COM jack.
When the current to be measured is under 400mA,
plug the red test lead into the mA jack; when the
current to be measured is over 400mA but under
10A, plug the red test lead into the 10A jack.
4.18.2 Set the rotary selector to the A range position.
4.18.3 Press the "SELECT" button to switch to AC
measurement. Then press the “RANGE” button
to choose the auto range or manual range mode.
4.18.4 Connect the test leads to the circuit for
measurement.
4.18.5 Take the reading on the main indicator of the LCD.
1) At the manual range mode, when only 'OL' or '-OL' is
shown on the LCD, it means the measurement has
exceeded the range. A higher range should be
selected.
2) At the manual range mode, when the scale of the
value to be measured is unknown beforehand, set
the range to the highest.
3) “ ” means the maximum current of the mA jack is
400mA and the maximum current of the 10A jack is
10A. At the 10A jack, current exceeding the limit will
blow the fuse.
4.19 Measuring Frequency
4.19.1 Plug the black test lead into the COM jack and
the red test lead into the Hz jack.
4.19.2 Set the rotary selector to the Hz range position
(or press the “Hz/DUTY” button at the AC/DC
V range to switch to Hz measurement).
4.19.3 Connect test leads to the two ends of the source
or load for measurement.
4.19.4 Take the reading on the main indicator of the LCD.
4.20 Measuring Duty
4.20.1 Plug the black test lead into the COM jack and
the red test lead into the Hz jack.
4.20.2 Set the rotary selector to the Hz range position.
4.20.3 Press the "Hz/DUTY" button to switch to DUTY
measurement (or press the “Hz/DUTY” button
at the AC/DC V range to switch to DUTY
measurement).
4.20.4 Connect test leads to the two end of the source
or load for measurement.
4.20.5 Take the reading on the main display of the LCD.

4.21 Measuring Resistance
Beware of Electrocution.
When measuring in-circuit resistance, make
sure that the power of the circuit under test
has been turned off and that all capacitors
have been fully discharged.
4.21.1 Plug the black test lead into the COM jack and
the red test lead into the jack.
4.21.2 Set the rotary selector to the Ω range position.
4.21.3 Press the "SELECT" button to switch to
measurement. Then press the “RANGE” button
to choose the auto range or manual range mode.
4.21.4 Connect the test leads to the ends of the resistor
or circuit for measurement.
4.21.5 Take the reading on the main indicator of the LCD.
1) At the manual range mode, when only 'OL' or '-OL' is
shown on the LCD, it means the measurement has
exceeded the range. A higher range should be selected.
2) When the input is open, 'OL' will appear on the LCD
to indicate that the range has been exceeded.
3) For measuring resistance above 1MΩ, it may take
a few seconds to get a steady reading. This is normal
for high resistance reading.
4.22 Measuring Capacitance
Beware of Electrocution.
To avoid electric shock, make sure that the
capacitors have been fully discharged
before measuring the capacitance of a
capacitor.
4.22.1 Plug the black test lead into the COM jack and
the red test lead into the jack.
4.22.2 Set the rotary selector to the range position.
4.22.3 After fully discharged the capacitor, connect the
test leads to the two ends of the capacitor for
measurement.
4.22.4 Take the reading on the main indicator of the LCD.
1) It may take some time (about 30 seconds for the
200μF range) for steady readings when measuring
high capacity.
2) Sometimes a reading may appear when the circuit
is open. In such case, press the “REL” button to
reset the reading and take measurement again.
4.23 Testing Diode
4.23.1 Plug the black test lead into the COM jack and
the red test lead into the jack.
4.23.2 Set the rotary selector to the Ω range position.
4.23.3 Press the "SELECT" button to switch to test.
4.23.4 Connect the red test lead to the anode and the
black test lead to the cathode of the diode for testing.
4.23.5 Take the reading on the main indicator of the LCD.