Mastech MAS830L User manual

MAS830L MAS830
MAS830B MAS838
Instruction Manual
DIGITAL MULTIMETER

Introduction
The instrument of this series is a small hand-held 3 1/2 digital
multimeter featuring stable, highly reliable and anti-drop
performance. It is provided with a LCD display of 15 mm
height for clear reading. The circuit design takes LSI double
integral A/D converter as its core under the protection of an
overload protection circuit, making it a superior and handy
instrument. It can be used to measure DC and AC voltage, DC
current, resistance, diodes, transistors, temperature and for
in-circuit continuity test.
Measurement features of the types of this series:
Features
MAS
830L
MAS
830
MAS
830B
MAS
838
Alternating Voltage
measurement V~




Direct Voltage
measurement V




Direct Current
measurement A




Resistance
measurement 




Diode measurement




hFE test




Continuity checking with
buzzer



Data hold




Backlight

1

1. Display
3 1/2 digit, 7 segment, 15mm high LCD.
2. Back light (option)
When this button is pushed, the Back light of display is
on. After about 5 seconds, the Back light is self-off. The
Back light is on again, just push this button once.
3. Function and range switch
This switch is used to select functions and desired
ranges as well as to turn on/off the meter.
4. Hold function
When this button is pushed, the display will keep the
last reading and “ ” symbol will appear on the LCD
until pushing it again.
5. “10A” jack
Plug in connector for red test lead for 10A measurement
6. “COM” jack
Plug in connector for black (negative) test lead.
7. VmA jack
Plug in connector for red (positive) test lead for voltage,
resistance and current (except 10A) measurements
2

FRONT PANEL
3

Safety Information
MAS830B, MAS830L, MAS830B and MAS838 Digital
Multimeters are designed based on ICE61010 600V(CATII)
and pollution degree 2.
To ensure the safe and accurate use, please read the
instruction manual carefully.
Safety Signs
Important safety information. Read the manual.
High voltage with danger
Ground.
Double insulation (Class II safety equipment).
Fuse must be replaced as per the specification herein.
Notices








The instrument can only be used in conjunction with the
probe for the compliance with safety standards. If the
probe needs replacing due to damage, the replacement
must be of the same type or the same electrical
specifications.
Do not exceed the input limit specified for each range.
When the instrument is measuring, do not touch the
input terminal not in use.
When a measurement range is uncertain, turn the
function/range switch to the maximum range position.
Before turning the function/range switch, make sure the
probe is open with the circuit being measured.
Before on-line resistance measurement, turn off all
power and discharge all capacitors.
Be careful when taking measurement of voltage higher
than 60V DC/30V AC. Remember to keep your fingers
behind the hand shield of the probe.
When measuring a TV set or switch power supply,
watch for pulse in the circuit that may damage the
multimeter. 4

Before measuring any transistor, make sure the probe is
not connected to any circuit being measured.
Before taking the measurement of voltage with the
probe, make sure there is no element connected to the
test socket of the transistor.
Maintenance







Before removing the rear cover, disconnect the probe
from the circuit to be measured.
To protect the internal circuit, replace the fuse with one
of the same specifications:
F1 250mA / 250V
F2 10A / 250V
Don’t use the instrument until the rear cover is placed
back and the screws are tightened.
Clean the housing of the instrument only with a wet rag
dripped with little detergent but never chemical solution.
In case of the any abnormality, stop using it and sent it
for maintenance.
Technical data
Accuracy: % of reading 5 digits, one year warranty.
Ambient temperature: 18℃to 28℃
Ambient humidity: 80%.
General features:
Maximum voltage between
terminals and earth ground
CATⅡ600V
Fuse protection
F1 250mA/250V F2 10A/ 250V
Power
9V battery, NEDA 1604 or 6F22
Display
1999
Overrange Indication
“1”
Polarity indication
“-” for negative polarity
Operating Environment
0 to 40℃
Storage temperature
-10℃to 50℃.
Low battery indication
“ ”appears on the display
Size
138mm×69mm×31mm
Weight
170g.
5

Direct current voltage measurement
Range
Resolution
Accuracy
200mV
100V
0.5% of rdg 3 digits
2V
1mV
0.5% of rdg 3 digits
20V
10mV
0.5% of rdg 3 digits
200V
100mV
0.5% of rdg 3 digits
600V
1V
0.8% of rdg 5digits
Overload Protection: 200mV range: 250V dc or rms.
The rest range: 600V dc or rms.
Direct current measurement
Range
Resolution
Accuracy
20A
0.01A
1% of rdg 3 digits
200A
0.1A
1% of rdg 3 digits
2mA
1A
1% of rdg 3 digits
20mA
10A
1% of rdg 5 digits
200mA
100A
1.5% of rdg 3 digits
10A
10mA
3% of rdg 10 digits
Overload Protection: F1 200mA/250V Fuse F2 10A/ 250V
*MAS838, no 20A positon
Alternative voltage measurement
Range
Resolution
Accuracy
200V
100mV
1.2 % of rdg 10 digits
600V
1V
1.2 % of rdg 10 digits
Overload Protection: 600V dc or rms.
Frequency range: 40Hz to 400Hz.
Display: Average(effective value of sinusoid)
RESISTANCE
Range
Resolution
Accuracy
200
0.1
0.8% of rdg 5 digits
2k
1
0.8% of rdg 2 digits
20k
10
0.8% of rdg 2 digits
200k
100
0.8% of rdg 2 digits
2M
1k
1.0% of rdg 5 digits
Maximum Open Circuit Voltage: 3.2V
Overload Protection: 250VDC or RMS.AC.
6

Diode and circuit on-off measurement
Range
Description
When the on-resistance is smaller than (70 30)),
the built-in buzzer will beep.
Display the approximate diode position voltage.
Overload Protection:250V DC or RMS.AC.
Temperature measurement
Range
Test Range
Measurement
Accuracy
℃
1℃
-20℃to 40℃
-0℃to 400℃
400℃to 1000℃
10% Range, 2 digits
1.0% Range, 3 digits
2.0% Range
TRANSISTOR hFE TEST (0-1000)
Range
Test Range
Test Current
Test Voltage
NPN & PNP
0-1000
Ib=10A
Vce=3V
Instructions
Notices before operation:
1. Plug the instruction, check the 9V battery, if it is slow, the
symbol will display, requiring battery replacement;
Otherwise follow the steps below.
2. The besides the probe jack indicates that the input
voltage or current should not exceed the specified limits to
protect the internal circuit.
3. Before measurement, turn the function/range switch to the
desired range.
Direct voltage measurement
1.
2.
Insert the red probe to the “V..mA” jack and the black
lead to the “COM” jack.
Turn the function/range switch to the range of V-and
connect the probe to the power supply or load to be
measured. The polarity touched by the red probe will be
on the display.
7

Direct current measurement
1.
2.
3.
4.
Place the black probe into the “COM” jack. For the
current to be measured not exceeding 220mA, put the
red one into the “V..mA” jack. For current to be
measured between 220mA and 10A, insert the red
probe into 10A jack.
Set the function/range switch to the desired A~ range,
and connect the probe in series with the load to be
measured. The current value and the polarity connected
to the red probe will be shown on the display.
8
Notice
1. If you do not knowthe measured voltage range in advance,
set the function/range switch to the maximum range, and
then gradually turn to smaller ranges until satisfactory
resolution.
2. If the display shows “1”, this indicates an overrange
measurement, and the switch should be set to a higher
range.
3. The symbol “”beside the probe indicates the
maximum input current is 200mA or 10A, depending on
the inserted jack. Overcurrent will blowthe fuse.
Notice
1. If you do not know the measured voltage range in advance,
set the function/range switch to the maximum range, and
then gradually turn to smaller ranges until satisfactory
resolution.
2. If the display shows “1”, this indicates an overrange
measurement, and the switch should be set to a higher
range.
3. Do not input a voltage of more than600V, it is capableof
indicating a higher voltage, but with the risk of damaging the
inside circuit.
4. When taking the measurement of high voltage, pay special
attention to avoid an electric shock.

Alternative voltage measurement
1.
2.
Place the red probe into the “V.. mA” jack and the
black probe into the “COM” jack.
Turn the switch to V~ and connect the probe to the
power supply or load to be measured.
Note: Refer to point 1, 2, 3 and 4 for direct current
voltage measurement.
Resistance measurement
1.
2.
3.
Place the back probe into the “COM” jack and red one
into the “V/ / HZ”jack.
Turn the switch to the “COM” jack, and connect the
probe to the resistor being measured and read the
result on the display.
Diode measurement
1.
2.
Insert the black lead to the “COM” jack the red one into
the “V..mA” jack.
Connect the red test lead to “V..mA” jack and the
black Turn the switch to the range, and connect
the red probe to the positive pole of the diode being
measured and the black one to the negative pole, read
the approximate forward voltage drop of the diode on
the display.
9
Notice
1. If the resistor being measured is greater than the maximum
value of the selected range, the display will show “1”,
requiring the selection of a higher range. It normally takes a
few seconds for the reading to get stable when measuring a
resistor larger than 1M.
2. In default of input, for instance, open circuit, thedisplay
shows “1”.
3. When measuring an online resistor, de-energized the
circuit being measured and discharged capacitors.

Transistor test
1.
2.
3.
Set the rotary switch at “hFE” position.
Determine whether the transistor under testing is NPN
or PNP and locate the emitter，base and collector leads.
Insert the leads into proper holes of the hFE socket on
the front panel.
Read the approximate hFE value at the test condition of
base current 10A and Vce 3V.
NOTE:
To avoid electrical shock, remove test leads from
measurement circuits before testing a transistor.
Circuit On-Off measurement
1.
2.
Insert the black probe to the “COM” jack the red one
into the “V..mA” jack.
Turn the switch to the position and connect the
probes in parallel with two points is less than 100, the
built-in buzzer will beep to indicate the continuity
between the two points.
Temperature measurement
1.
2.
Turn the switch to the ℃position and insert the black
probe of the thermocouple sensor into COM jack the red
one into the V..mA jack. Place the operating terminal
(temperature measured and directly read the
temperature value in ℃on the display.
When the switch is turned to the ℃position and the
sensor is in an open circuit, the display shows room
temperature.
Replacement of battery and fuse
1. Under normal conditions, it is unnecessary to replace the
fuse. Don’t replace it until the probes are unplugged and
the power is shut down. Take out the two screws of the
rear cover to remove the housing.
2. The specification of the fuse is:
F1 250mA/250V, F2 10A/250V.
10

The replacement should be of the same specification.
3. The battery for this multimeter is 9V NEDA 1604 or 6F22.
The replacement should be of the same specification.
4. Don’t put the instrument into use until the rear cover is
screwed after replacing battery or fuse.
Attachments
Instruction manual: one copy
Probe: one pair
Package: one piece
9 V battery NEDA 1604 6F22: one provided (in the
multimeter)
K thermocouple sensor: one piece (MAS838 only)
Rubber case (optional)
11
WARNING
To avoid electric shock, make sure the probe are disconnected
from the measured circuit before removing the rear cover. Make
sure the rear cover is tightly screwed before using the instrument.