Mastech ms6231 User manual

MS6231
DIGITAL
ENGINE ANALYZER
OPERATOR ’ S MANUAL
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 ( ( ( 600V 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, the digital meter 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.
( 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 Test 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 each range of measurement.
1.2.3 When the meter is linked to a measurement circuit, do not touch unused terminals.
1.2.4 At the manual range, 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 600V 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 transform switch is in the current,
resistance, temperature, diode or continuity mode. Doing so can damage the meter.

1.2.8 Before rotating the transform switch to change functions and ranges, disconnect test leads from the
circuit under test.
1.2.9 Never perform resistance, temperature, diode and continuity measurements on live circuits.
1.2.10 Never use the meter under the condition of the explosive air, steam or dirt.
1.2.11 If any faults or abnormalities are observed, the meter can not be used any more and it has to be
checked out.
1.2.12 Never use the meter unless the rear case is in place and fastened fully.
1.2.13 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 class ( ( ）.
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
AC Alternating current
DC Direct current
Diode
Continuity buzzer
AC or DC (alternating current or direct current)
Engine dwell
RPM Round per minute
× 10 Reading multiplies 10
Measurement with clamp (optional), widening the field of applications of the meter
℃Centigrade
℉Fahrenheit
MAX-H The maximum value is being held.
DATA-H This indicates that the display data is being held.
AUTO Auto range
The battery is not sufficient for proper operation.
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 Do not use abrasives or solvents on the meter, use a damp cloth and mild detergent only.
1.4.5 Always set the power switch to the OFF position when the meter is not in use.
1.4.6 If the meter is to be stored for a long period of time, the batteries should be removed to prevent
damage to the unit.
2. DESCRIPTION

- This meter is a portable professional measuring instrument with handsome LCD and back light easily
reading.
- Single operation of a transform 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 auto range and manual range.
- This meter has function of auto warning.
- This meter has function of auto power off.
- This meter is with the functions of data hold and maximum value hold.
- When using, it can show ranges engineering unit enunciators measuring results.
2.1 NAMES OF COMPONENTS
⑴LCD Display
⑵ON/OFF Button
⑶RANGE Button
⑷FUNC. Button
⑸Transform Switch
⑹10A Jack
⑺INPUT Jack
⑻COM Jack
⑼Panel
⑽Button
⑾DATA-H Button
⑿MAX.H Button
2.2 SWITCH, BUTTONS AND INPUT JACK ELUCIDATION
( ON/OFF Button
This Button is used to the switch of power.

(1)
(2)
(3)
(4)
(5)
(6)
(10)
(11)
(9)
(7)
(8)
(12)
( RANGE Button
This button is used to transform Auto range or manual range.
( FUNC. Button
This button is used to transform function.
( DATA-H Button
This Button is used to the switch of data hold.
( MAX.H Button
This Button is used to the switch of maximum value hold.
( Button
This button is used to the switch of back light.
( Transform Switch
This switch is used to select functions and desired ranges.
( 10A Jack
Input terminal for current 0 ~ 10A.
INPUT Jack Input terminals except A.
COM Jack
Common terminal for measurement.

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
3.1.1 Auto ranges and manual range.
3.1.2 Overrange protection for all ranges.
3.1.3 Max. Voltage Between Terminals And Earth Ground: 600V DC or AC
3.1.4 Operating Altitude: 2000 meters (7000 ft.) maximum
3.1.5 Display: 16mm LCD
3.1.6 Max. Show Value: 1999 (3 1/2)
3.1.7 Polarity Indication: ‘ - ’ indicates negative polarity.
3.1.8 Overrange Indication: Display ‘ OL ’
3.1.9 Sampling Time: approx. 0.4 second
3.1.10 Unit showing: showing of function and electrical capacity.
3.1.11 Low Battery Indication: ‘ ’ displayed
3.1.12 Auto power off time: 15 min.
3.1.13 Power Supply: 1.5V × 3 AAA battery.
3.1.14 Operating Temperature: 0 ℃to 40 ℃（32 ( F to 104 ( F ）
3.1.15 Storage Temperature: -10 ℃to 50 ℃（10 ( F to 122 ( F ）
3.1.16 Dimension: 158 × 74 × 32 mm
3.1.17 Weight: approx. 250g （including battery ）
3.2 ELECTRICAL SPECIFICATIONS
Circumstance Temperature: 23 ( 5 ℃Relative Humidity: < 75%
3.2.1 DC Voltage
Range Resolution Accuracy
200mV 0.1mV
2V 0.001V
20V 0.01V
(（0.7% of rdg + 2 digits ）
200V 0.1V
600V 1V
- Input Impedance: 10M (
- Overload Protection:
200mV range: 250V DC or AC rms, 2V-600V ranges: 600V DC or AC rms.
- Max. Input Voltage: 600V DC

3.2.2 AC Voltage
Range Resolution Accuracy
200m
V
0.1mV
2V 0.001V
(（0.8% of rdg + 3 digits ）
20V 0.01V
200V 0.1V
600V 1V ( （1.0% of rdg + 3 digits ）
- Input Impedance: 10M (
- Overload Protection:
200mV range: 250V DC or AC rms, 2V-600V ranges: 600V DC or AC rms.
- Frequency Range: 40 to 400Hz
- Response: Average, calibrated in rms of sine wave.
- Max. Input Voltage: 600V rms AC
3.2.3 DC Current
Range Resolution Accuracy
2.000
A
0.001A
(（2.0% of rdg + 10
digits ）
10.00
A
0.01A
- Overload Protection: unfused.
- Max. Input Current:: 10A
- voltage drop ：2A range: 20mV,
10A range: 200mV
3.2.4 AC Current
Range Resolutio
n
Accuracy
2.000
A
0.001A ( （3.0% of rdg + 10 digits ）
10.00
A
0.01A
- Overload Protection: unfused.
- Max. Input Current:: 10A
- Frequency Range: 40 to 400Hz
- Response: Average, calibrated in rms of sine wave.
- voltage drop ：2A range: 20mV,
10A range: 200mV
3.2.5 DC Current （with clamp, optional ）
Range Resolut
ion
Accuracy
mete
r 200A
0.1mV
/0.1A
(（1.2 % of rdg + 3
digits ）
(DC)
Cla
0
to 200A
0.1A
/0.1mV
Typical ( （2.0 % ）

mp
mete
r 2000A
1mV/1
A
(（1.2 % of rdg + 3
digits ）
(DC)
Cla
mp
0
to
2000A
1A
/1mV
Typical ( （2.0 % ）
- Overload Protection: 250V DC or 250V rms AC.
- Max. Input Voltage: 200mV
3.2.6 AC Current （with clamp, optional ）
Range Resolut
ion
Accuracy
mete
r 200A
0.1mV
/0.1A
(（1.5 % of rdg + 5
digits ）
(DC)
Cla
mp
0
to 200A
0.1A
/0.1mV
Typical ( （3.0 % ）
mete
r 2000A
1mV/1
A
(（1.5 % of rdg + 5
digits ）
(DC)
Cla
mp
0
to
2000A
1A
/1mV
Typical ( （3.0 % ）
- Overload Protection: 250V DC or 250V rms AC.
- Max. Input Voltage: 200mV
- Frequency Range: 40 to 400Hz
- Response: Average, calibrated in rms of sine wave.
3.2.7 Resistance
Range Resolutio
n
Accuracy
200 ( 0.1 ( ( （1.0% of rdg + 3 digits ）
2k ( 0.001k ( ( （1.0% of rdg + 1 digit ）
20k ( 0.01k ( ( （1.0% of rdg + 1 digit ）
200k ( 0.1k (
(（1.0% of rdg + 1 digit ）
2M ( 0.001M (
(（1.0% of rdg + 1 digit ）
20M ( 0.01M ( ( （1.0% of rdg + 5 digits ）
- Open Circuit Voltage: 0.25V
- Overload Protection: 250V DC or 250V rms AC
3.2.8 Continuity
Range Function
Built-in buzzer will sound, if
resistance is lower than 50 ( .
- Open circuit voltage: approx. 0.5V
- Overload Protection: 250V DC or 250V rms AC

3.2.9 Temperature
Range -20 ℃to 1000 ℃
Resoluti
on
1℃
-20 ℃to 0 ℃(（5% of rdg +
4digits ）
Accurac
y
0℃to 400 ℃(（1% of rdg +
3digits ）
400 ℃to
1000 ℃
(（2% of rdg +
3digits ）
Range -0 ℉to 1800 ℉
Resoluti
on
1℉
-0 ℉~50 ℉(（5% of rdg +
4digits ）
Accurac
y
50 ℉~750 ℉(（1% of rdg +
3digits ）
750 ℉~1800
℉
(（2% of rdg +
3digits ）
- Overload Protection: 250V DC or rms AC
3.2.10 Engine Dwell
Range Resolution Accuracy
4CYL 0.1 º ( （3 º ）
6CYL 0.1 º ( （3 º ）
8CYL 0.1 º
(（3 º ）
- Overload Protection: 250V DC or rms AC
3.2.11 Engine Rev
Range Resolutio
n
Accuracy
4CYL 10RPM
6CYL 10RPM ( （3.0% of rdg + 3 digits ）
8CYL 10RPM
- Overload Protection: 250V DC or rms AC
3.2.12 Diode
Rang
e
Resolutio
n
Function
1mV Display :read approximate
forward voltage of diode.
- Forward DC Current: approx. 1mA
- Reversed DC Voltage: approx.1.5V
- Overload Protection: 250V DC or rms AC
4. OPERATING INSTRUCTION
4.1 POWER-UP
Press the “ ON/OFF ” button to turn the meter ON or OFF.

4.2 DATA HOLD
If you need data hold when measuring, you can put on “ DATA-H ” button, it will hold the reading; if you put
the button again, data hold is not continue.
4.3 MAXIMUM VALUE HOLD
If you need data hold when measuring, you can put on “ MAX.H ” button, it will hold the maximum value; if
you put the button again, maximum value hold is not continue.
4.4 FUNCTION TRANSFORM
Put down the "FUNC." when measuring the current and voltage. Meter will be transformed between DC
and AC range. Put "FUNC." when measuring the temperature, meter will transform between ℃and ℉
range. Put "FUNC." when measuring the diode and continuity, meter will transform among them.
4.5 RANGE TRANSFORM
The auto range is used when measuring the current, voltage and resistance. Put down the "RANGE" if
the manual range is needed. Each time you put down, range will go upward; the minimum range is
transformed if "RANGE" is put down at the maximum range. If the "RANGE" is put down more than two
seconds, auto range is used again.
4.6 BACK LIGHT
If the light is dark to make the reading difficult when measuring, you can press “ ” button to turn on the
back light, which will last for 15 seconds. Continuous pressing the button for two seconds will turn off 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 15 seconds and it will off automatically after 15 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 3.8V, it will show “ ” . But if you use back light at the same time,
maybe “ ” will come up even if the battery voltage is more than 3.8V, 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.
4.7 AUTO WARNING
If the input voltage is larger than 2V at the range and if the input current is larger than 10A, buzzer
will have a long sound
4.8 AUTO POWER OFF
( If there ’ s no any operation within fifteen minutes after power is on, meter will auto power off with five
short sounds and a long sound in a minute.
( After auto power off, if stir the transform switch or put down any button of “ FUNC. ” ,
“ DATA-H ” , ” MAX.H ” , ” RANGE ” , meter will recover the working condition. ( If presses the “ FUNC ” when
power is on, auto power off disable.
4.9 PREPARATION FOR MEASUREMENT
4.3.1 Put on the “ ON/OFF ” button. If the battery voltage is less than 3.8V, display will show “ ” , the
battery should be changed at this time.
4.3.2 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.
4.3.3 Select a function and a range for the item to be measured through rotating the transform switch

accordingly. When the value scale to be measured is unknown beforehand, set the range selector at the
highest position.
4.3.4 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.
4.10 MEASURING DC VOLTAGE
WARNING
You can ’ t input the voltage which more than
600V 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.
4.10.1 Connect the black test lead to the COM jack and the red test lead to the INPUT jack.
4.10.2 Set the transform switch at the V range position.
4.10.3 Put down the "FUNC." to enter the DC measurement. Auto range or manual range can be
transformed by
putting the “ RANGE ” .
4.10.4 Connect test leads across the source or load under measurement.
4.10.5 You can get a reading from LCD display. The polarity of the red test lead connection will be
indicated.
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.
( At the manual range mode, when only the figure ‘ OL ’ is displayed, it indicates overrange situation and