Mastech MS2225A User manual

Digital Clamp Power Meter
Operation Manual
MS2225A
CAT III

CONTENTS CONTENTS
1. Safety information ..............................................01
1.1 Preparation ...............................................01
1.2 Use ...........................................................02
1.3 Mark ..........................................................03
1.4 Maintenance .............................................04
2. Description .........................................................04
2.1 Name of parts ...........................................06
2.2 Descriptions of switch, button and input jack
..................................................................07
2.3 LCD display ..............................................09
3. Specification .......................................................11
3.1 General .....................................................11
3.2 Technical specifications ............................12
3.2.1 Alternating current .........................12
3.2.2 Inrush current ................................12
3.2.3 DC voltage ....................................13
3.2.4 AC voltage .....................................13
3.2.5 Frequency .....................................14
3.2.6 Duty ratio .......................................15
3.2.7. Resistance ...................................16
3.2.8 Circuit continuity test .....................16
3.2.9. Capacitance .................................16
3.2.10 Diode test ....................................17
3.2.11 Single-phase active power ..........17
3.2.12 Single-phase apparent power .....18
3.2.13 Single-phase reactive power .......18
3.2.14 Power factor ................................19
3.2.15 Harmonics measurement ............19
4 Operation Guide .................................................19
4.1 Reading holding ........................................19
4.2 Manual range ............................................20
4.3 Switchover of frequency and duty ratio .....20
4.4 Selection of maximum/minimum value
measurement ...........................................21
4.5 Function switching ....................................21
4.6 Measurement of relative value .................22
4.7 LINK measurement ...................................22
4.8 REC function ............................................23
4.9 ▼function ..................................................23
4.10 ▲function ................................................24
4.11 INRUSH measurement ...........................24
4.12 Back-light and clamp lighting .................24
4.13 Automatic shutdown ...............................25

01
4.14. Measurement preparation ......................25
4.15 AC current measurement ........................26
4.16. Voltage measurement ............................28
4.17 Measuring frequency and duty ratio ........30
4.18 Resistance measurement .......................34
4.19 Diode test ................................................36
4.20 Circuit continuity test ...............................38
4.21 Capacitance measurement .....................40
4.22 Measurement of inrush current ...............42
4.23 NCV measurement ................................. 44
4.24 Active power measurement .....................46
4.25 Apparent power measurement ................48
4.26 Power factor measurement .....................50
4.27 Phase angle measurement .....................52
4.28 Harmonics measurement (voltage signal)
..............................................................53
4.29 Harmonics measurement (current signal)
...............................................................56
5 Maintenance .......................................................58
5.1 Battery replacement ..................................58
5.2 Replacing Test Leads.............................. 58
6 Attachments ........................................................59
CONTENTS 1. Safety information
Please pay special attention when using this meter,
improper use may result in electric shock or damage to the
meter. Please follow the common safety rules, and fully
comply with the safety precautions specified in the user
manual.
To make full use of the meter, and ensure safe operation,
please read carefully and follow the application methods in
this specification.
WARNING
This meter conforms to IEC 61010 Safety Requirements of
Electronic Measuring Instrument. It causes secondary pollution,
and the over-voltage standard is CAT IV 600 V and
CAT III 1000V. Please abide by the safe operation guidance to
ensure the safety use of the meter. Appropriate use and
protection of the meter will bring you satisfactory service
1.1 Preparation
1.1.1 The users must comply with the following safety
regulations when using the meter:
- General electric shock protection
- Prevent the misuse of the meter
1.1.2 After receiving the meter, check whether it is damaged in
the transportation.
1.1.3 Check and verify whether the meter is damaged after
being stored and shipped in poor condition.
1.1.4 The probe must be in good condition. Check whether the
insulation of the probe is broken and the metal wire of the
conductor is exposed before using.

1.1.5 The probe provided with the meter can ensure the safe
use, and it must be replaced with the same probe or the
probe of the same grade, if necessary.
1.2 Use
1.2.1 You must use the meter according to requirements of
correct functions and measuring range.
1.2.2 Do not exceed the indicated value of protection scope of
each measuring range during the measurement.
1.2.3 Do not touch the top of the probe when the meter is
connected for measuring the circuit.
1.2.4 During the measurement, if the measured voltage is
higher than 60V DC or 30 V AC (effective value), you
should keep your fingers behind the probe protector all
the time.
1.2.5 Do not measure the voltage when the AC voltage
between the measuring terminal and the ground is
greater than 750 V.
1.2.6 Select the highest range of the manual range if you don't
know the measured value in advance.
1.2.7 Remove the probe from the measured circuit before
rotating the change-over switch to change the measuring
function.
1.2.8 Do not perform the live line measurement for the
resistance, capacitance, diodes and circuit continuity.
1.2.9 Do not connect the meter to the voltage source during
the current, resistance, capacitance, diodes and circuit
continuity test.
1.2.10 Do not measure the capacitance before the capacitor is
fully discharged.
1.2.11 Do not use this meter near the explosive gas, steam or
dust.
1.2.12 In case of any abnormality or fault, please stop using
the meter.
1.2.13 Do not use this meter, unless the bottom case and the
battery cover are fully fastened in situ.
1.2.14 Do not store or use this meter in direct sunlight, high
temperature, or high humidity.
1.3 Mark
Note-Important safety information, refer to the
instruction manual.
Application around and removal from UNINSULATED
HAZARDOUS LIVE conductors is permitted.
Complies with European (EU) safety standards
Conforms to UL STD. 61010-1, 61010-2-032,
61010-2-033; Certified to CSA STD C22.2 NO.
61010-1, 61010-2-032,61010-2-033
Earth (ground) TERMINAL
CAT III
It is applicable to test and measuring circuits
connected to the distribution part of the
building's low-voltage MAINS installation.
Equipment protected throughout by double
insulation or reinforced insulation.
Alternating current
Both direct and alternating current
MEASUREMENT CATEGORY IV is applicable to
test and measuring circuits connected at the source
of the building’s low-voltage MAINS installation.
CAT IV
02 03

04 05
1.4 Maintenance
1.4.1 Do not try to open the bottom case of the meter for
 adjustment or repair. These operations can only be
 performed by the technicians who understand the meter
 and the shock hazard adequately.
1.4.2 Please remove the probe from the measured circuit
 before opening the bottom case or the battery cover of
 the meter.
1.4.3 In order to avoid the electric shock caused by the
 incorrect reading, when the meter displays ""
replace the battery immediately.
1.4.4 Use wet cloth and mild detergent to clean the meter, and
do not use the abrasive or solvent.
1.4.5 Turn off the power of meter when you don't use it, rotate
the range switch to the OFF gear.
1.4.6 Take off the battery to prevent the damage to the meter,
if you do not use it for a long time.
2. Description
-MS2225A single-phase clamp-type harmonic power meter is
hand-type intelligent power measuring meter, which combines
the digital multimeter and power measurement with Bluetooth
function. The range switch with one-handed performance is
convenient for the measurement, and this meter can perform
the functions of overload protection and low battery indicator.
- The meter can be used for the measurement of the
alternating current, alternating voltage, direct voltage,
frequency, duty ratio, resistance and capacitance and circuit
continuity, diode test, non-contact voltage detection, as well as
the measurement of the active power, reactive power,
apparent power, power factor, harmonics measurement and
phase angle measurement.
- The meter supports the auto range and manual range.
- The meter supports reading holding.
- The meter supports maximum measurement.
- The meter supports minimum measurement.
- The meter supports relative measurement.
- The meter supports Bluetooth.
- The meter supports data storage.
- The meter supports back-light and clamp lamp.
- The meter supports automatic shutdown.
- The meter supports low voltage indicator.

2.1 Name of parts
(1) Current clamp: for current measurement.
(2) Clamp lamp
(3) Faceplate
(4) Trigger
(5) Button for data storage and switch of auto and
manual range
(6) Button for maximum/minimum selection
(7) Button for function switch
(8) Button for reading holding/back-light
(9) Button for frequency and duty ratio measurement,
inrush current and up
(10) Button for Bluetooth function, relative
measurement and down
(11) Change-over switch
(12) NCV indicator light
(13) LCD display
(14) Input jack of resistance, capacitance, voltage,
frequency, diode and continuity.
(15) Jack of common terminal
12
11
1
2
3
4
5
6
7
8
14
9
10
13
15
2.2 Descriptions of switch, button and
input jack
FUNC button: for switching the measurement function.
B.L/HOLD button: the readings will be held by the short press,
and the back-light will be turned on by long press. The back-
light and clamp lamp will be turned on at the same time by
pressing the B.L/HOLD button in the current gear and in the
power gear on the current interface.
REC/RANGE button: short press for switching between auto
and manual range mode, and long press for data storage.
LINK/REL/▼ button
1) Long press for validating Bluetooth in all gears.
2) Short-press in the harmonic measurement interface at KW
and W gears to scroll down, and to switch between the 1st
06 07

08 09
harmonic and 20th harmonic. At the KW and W gears, short-
press the function key in the maximum/minimum value
measurement interface to scroll down, and switch and display
the maximum/minimum value.
3) Short press on alternating current, AC/DC voltage and
capacitance for relative value measurement mode.
Hz%/INRUSH/▲button
1) Short press on alternating current, alternating voltage and
HZ% gear for the switch among alternating current or
alternating voltage, frequency and duty ratio.
2) Short-press on the harmonic measurement interface at KW
and W gears to scroll up, and switch between the 1st harmonic
and 20th harmonic. At the KW and W gears, short-press the
function key in the maximum/minimum value measurement
interface to scroll up, and switch and display the
maximum/minimum value.
3) Long press on the alternating current gear for switching to
the measurement mode of inrush current.
MAX/MIN button: for the switch between the
maximum/minimum measurement.
OFF gear: for power off.
INPUT jack: input terminal of voltage, resistance, frequency,
duty ratio, capacitance, diode and circuit continuity.
COM jack: common terminal of voltage, resistance, frequency,
duty ratio, capacitance, diode and circuit continuity.
Change-over switch: for selection of functions and ranges.
2.3 LCD display
Alternating current/Direct current
Diode and continuity
Auto range mode
Status of maximum measurement
Status of minimum measurement
Status of relative measurement
Status of automatic shutdown
LOW BATTERY
Status of reading holding
HOLD
HZ Frequency measurement
Percentage (duty ratio)
Millivolt, volt (voltage)
Ampere (electric current)
Nano farad, microfarad and millifarad
Ohm, kilo-ohm and megohm (resistance)
Hertz, kilohertz and megahertz (frequency)

Non-contact voltage detection
Watt and kilowatt (active power)
Unit of apparent power
Reactive power
Phase angle
Peak value measurement
Total harmonic distortion
Total harmonic distortion F (relative to
fundamental wave)
Total harmonic distortion r (relative to
actual effective value)
Power factor
Phase
Status of inrush current measurement
Data recorder
Bluetooth function
Leading phase angle
Lagging phase angle
Hour (time unit)
Negative sign
W,KW
VA, KVA
Var, KVAr
O
PEAK
THD
H01F
H01r
COSФ
Phase
INR
REC
LEAD
LAG
h
3. Specification
Recalibrate the meter under the conditions of 18°C~28°C
and the relative humidity less than 75%, with the
calibration cycle of 1 year.
3.1 General
Auto range and manual range.
Full-scale overload protection.
Maximum allowable voltage between measured end
and the ground: 1000 V DC or 750 V AC.
Working height: less than 2,000 m.
Displayer: LCD.
Maximum displayed value: 5999 dgt.
Polar indication: self-indicating, "-" means negative
polarity.
Over-range display: '0L' or '-0L'.
Sampling time: around 3 times/s.
Unit display: display the functions and the unit of
electric quantity.
Time of automatic shutdown: 30 minutes.
Power supply: DC power supply 9 V.
Type of battery: NEDA 1604 or 6F22.
Under-voltage indication of battery: LCD display
symbol.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15 Temperature coefficient: less than 0.1×degree of
accuracy/°C.
10 11

16 Working temperature: 18°C~28°C.
Storage temperature: -10°C~50°C.
17
18
19
Dimension: 238×92×50 mm.
Weight: around 420 g (including battery).
3.2 Technical specifications
Environmental temperature: 23±5°C relative
humidity: ≤ 75%
3.2.1 Alternating current
Range Resolution Accuracy
±(2.0% rdg+ 8 dgt)
60A 0.01A
600A 0.1A
1000A 1A
- Maximum input current: 1000A AC
- Frequency range: 40~400 Hz
3.2.2 Inrush current
Range Resolution Accuracy
<60 A (for reference only)
±(5% rdg+ 60 dgt)
60A 0.01A
600A 0.1A
1000A 1A
Integral time: 100 ms; measurement range: 20~1000 A;
frequency range: 40~400 Hz
3.2.3 DC voltage
Range Resolution Accuracy
±(0.5% rdg+ 5 dgt)
-Input impedance: 10M
-Maximum input voltage: 750 V AC (effective value) or
1000 V DC.
6V
60V
600V
1000V
0.001V
0.01V
0.1V
1V ±(0.8% rdg+ 4 dgt)
3.2.4 AC voltage
Range Resolution Accuracy
±(0.6% rdg+ 4 dgt)
- Input impedance: 10M
- Maximum input voltage: 750 V AC (effective value) or
1000 V DC.
- Frequency range: 40~400 Hz.
±(0.8% rdg+ 4 dgt)
6V
60V
600V
750V
0.001V
0.01V
0.1V
1V
Note:
Under the small voltage range, there might be reading on
the meter before the probe is connected to the measured
circuit.
The above phenomenon is normal because the meter has
high sensitivity and it has no influence on the actual
measurement result.
12 13

3.2.5 Frequency
3.2.5.1 Frequency measurement with clamp
(at A gear):
Range Resolution Accuracy
±(1.5% rdg+ 5 dgt)
99.99Hz
999.9Hz
0.01Hz
0.1Hz
- Measurement range: 10 Hz~1 kHz
- Range of input signal: ≥ 20A AC (the input current is
increased with the measured frequency)
- Maximal input current: AC 1000 A (effective value)
3.2.5.2 At V gear:
Range Resolution Accuracy
±(1.5% rdg+ 5 dgt)
99.99Hz
999.9Hz
9.999kHz
0.01Hz
0.1Hz
0.001kHz
- Measurement range: 10 Hz~10kHz
- Range of input voltage: ≥ 1 V AC (effective value) (the
input voltage is increased with the measured frequency)
- Input impedance: 10MΩ
- Maximum input voltage: 750 V AC (effective value)
3.2.5.3 At HZ/DUTY gear:
Range Resolution Accuracy
±(0.3% rdg+ 5 dgt)
9.999Hz
99.99Hz
999.9Hz
9.999kHz
99.99KHZ
999.9KHZ
9.999MHZ
±(0.3% rdg+ 5 dgt)
0.001Hz
0.01Hz
0.1Hz
0.001kHz
0.01kHZ
0.1KHZ
0.001MHZ
- Overload protection: 1000 V DC or 750 V AC (effective
value)
- Range of input voltage: ≥ 2 V (the input voltage is
increased with the increase of the measured frequency)
3.2.6 Duty ratio
Range Resolution Accuracy
±(3.0% + 3 )
0.1 - 99.9% 0.1%
- Frequency response: 10 ~ 1 kHz.
- Range of input current: ≥ 20 A AC (effective value)
-Maximal input current: AC 1000 A
3.2.6.1 At A gear (from the clamp):
3.2.6.2 At V gear:
- Frequency response: 10 ~ 10kHz.
- Range of input voltage: 1 V AC.
- Input impedance: 10MΩ
- Maximum input voltage: 750 V AC (effective value)
- Frequency response: 10 ~ 10MHz.
- Range of input voltage: ≥ 2V AC (effective value) (the
input voltage is increased with the measured frequency)
- Maximum input voltage: 250V AC (effective value)
3.2.6.3 At HZ/DUTY gear:
14 15

16 17
3.2.7. Resistance
Range Resolution Accuracy
±(0.8% rdg+ 3 dgt)
600Ω
6kΩ
60kΩ
600kΩ
6MΩ
60MΩ
0.1Ω
0.001kΩ
0.01kΩ
0.1kΩ
0.001MΩ
0.1MΩ±(2% rdg+ 5 dgt)
- Open-circuit voltage: around 0.78 V
- Overload protection: 1000 V DC or AC (effective value)
3.2.8 Circuit continuity test
Range Resolution Function
600Ω0.1Ω
If the resistance of measured
circuit is less than 50Ω, the
buzzer inside the meter will
send a sound.
- Open-circuit voltage: around 1.48V
- Overload protection: 1000 V DC or 750 V AC (effective
value)
3.2.9. Capacitance
Range Resolution Accuracy
±(3.0% rdg+ 5 dgt)
9.999nF
99.99nF
999.9nF
9.999µF
99.99µF
0.001nF
0.01nF
0.1nF
0.001µF
0.01µF
±(3.0% rdg+ 5 dgt)
999.9µF
9.999mF
99.99mF
0.1µF
0.001mF
0.01mF
- Overload protection: 1000 V DC or 750 V AC (effective
value)
3.2.10 Diode test
Range Resolution Function
3V 0.001V
Display the approximate
value of diode forward
voltage
- DC forward current is around 1 mA
- DC reverse voltage is around 3.2 V
- Overload protection: 1000 V DC or 750 V AC (effective
value)
3.2.11 Single-phase active power
Range Resolution Accuracy
±(3.0% rdg+ 5 dgt)
3W
100W
4000W
10kW
100kW
750kW
0.01W
0.1W
1W
0.01kW
0.1kW
1kW

18 19
Minimum input current: 1 mA, and minimum input
voltage: 1 V.
3.2.12 Single-phase apparent power
Range Resolution Accuracy
±(3.0% rdg+ 5 dgt)
0.01VA
0.1VA
1VA
0.01kVA
0.1kVA
1kVA
3VA
100VA
4000VA
10kVA
100kVA
750kVA
Minimum input current: 1 mA, and minimum input
voltage: 1 V.
3.2.13 Single-phase reactive power
Range Resolution Accuracy
±(3.0% rdg+ 5 dgt)
Minimum input current: 1 mA, and minimum input
voltage: 1 V.
3W
100W
4000W
10kW
100kW
750kW
0.01W
0.1W
1W
0.01kW
0.1kW
1kW
3.2.14 Power factor
Range Resolution Accuracy
0.3 ~ 1 capacitive
0.3 ~ 1 inductive
0.001
0.001 ±(3.0% rdg+ 5 dgt)
Minimum input current: 1 mA, and minimum input
voltage: 1 V.
3.2.15 Harmonics measurement
Range
1
2-6
7-8
9-10
11-15
16-20
±(3.0% rdg+ 10 dgt)
±(3.5% rdg+ +10 dgt)
±(4.5% rdg+ 10 dgt)
±(5.0% rdg+ 10 dgt)
±(7.0% rdg+ 10 dgt)
±(10.0% rdg+ 10 dgt)
Accuracy of harmonic electrical level
Minimum input current: 1 mA, and minimum input
voltage: 1 V.
4. Operation Guide
4.1 Reading holding
1) During the measurement, if the reading shall be held,
short-press the "HOLD/B.L" key to lock the display
value of the display, and short-press the "HOLD/B.L"
key to unlock the kept reading.

4.2 Manual range
The RANGE key is used for setting the auto/manual range,
and this key can be activated through triggering. Its
startup default state is auto range. Press the key once to
switch to the manual range. In the manual range mode,
move the meter to the next higher gear after pressing the
key once, and after moving to the highest gear, press the
key continuously to move the meter to the lowest gear.
Perform the cyclic operations in sequence. If press the
key for more than 2 s, the meter will be switched to the
state of auto range.
Note:
During the measurement of diode, continuity test,
capacitance, and frequency KW, W and NCV gear, the
manual range is unavailable.
4.3 Switchover of frequency and duty ratio
1) When the meter is at AC current gear, short-press the
"Hz/%/INRUSH/▲" key, the meter can be in Hz
measurement state to measure the frequency of
measured AC voltage and current signals. Then,
short-press the "Hz/%/INRUSH/▲" key again, the meter
will be in DUTY measurement state to measure the duty
ratio of measured voltage and current signals. If the
meter is in HZ/% gear, short-press "Hz/%/INRUSH/▲"
key to switch the meter to the HZ and DUTY states
circularly.
2) If the meter is in AC current and AC/DC voltage gear,
short-press the "Hz/%/INRUSH/▲" key, the meter will
be in the voltage and current measurement state.
4.4 Selection of maximum/minimum value
measurement
1) Press the "MAX/MIN" key in the kW and W gear, the
interface will simultaneously display the maximum and
minimum values obtained after the test for a period of
time, and then press the ▲or ▼key on this interface to
enter the interface displaying the time of record. After
that, the specific time period of these maximum and
minimum values will be displayed.
2) When the meter is at AC current gear, AC/DC voltage
gear and resistance gear, press the "MAX/MIN" to enter
the MAX mode and measure the maximum value all the
time; press "MAX/MIN" key once again to enter the state
for measuring the minimum value; and then press the
"MAX/MIN" key for the third time to exit the
measurement mode of maximum and minimum value.
Note:
1) The meter is in manual range mode under the
measurement states of max/min value.
4.5 Function switching
1) Long-press the FUNC key in the power measurement
interface to enter the power, voltage and current
measurement interface.
2) Short-press the FUNC key in the power measurement
interface to enter the active power, apparent power,
reactive power, power factor and phase angle
measurement interface.
3) When the meter is at power gear, short-press the FUNC
key in the voltage measurement interface to enter the
voltage effective value, harmonic, harmonic distortion
rate THD-R and harmonic distortion rate THD-F
measurement interface.
20 21

22 23
4) When the meter is at power gear, short-press the FUNC
key in the current measurement interface to enter the
current effective value, harmonic, harmonic distortion
rate THD-R and harmonic distortion rate THD-F
measurement interface.
5) When the meter is at DC/AC gear, short-press the FUNC
key to switch between the DC voltage measurement and
AC voltage measurement interface.
6) When the meter is at resistance/diode/buzzer/
capacitance gear, short-press the FUNC key to switch
among resistance, diode, buzzer and capacitance
measurement.
4.6 Measurement of relative value
1) Short-press the LINK/REL/▼ key at AC current, AC/DC
voltage and capacitance gears to enter the relative
value measurement mode and store the current
displaying value in memory as the reference value. For
the sequent measurement, the displayed value is the
difference value between the input value and reference
value, i.e. REL▲ (current reading) = input value -
reference value.
2) This function of relative value measurement only can be
available in the manual measurement mode.
4.7 LINK measurement
At any gear (excluding OFF gear), long-press LINK/REL/▼
to turn on the Bluetooth of meter. Then open the
corresponding APP (iOS or Android) of the meter through
mobile phone or other equipment and search the signal to
link them. After the linking, the APP will display the
content displayed on meter in real time. Long-press the
LINK/REL/▼ key once again, the Bluetooth of meter will
be turned off and the meter will be disconnected from the
APP.
4.8 REC function
The meter performs the functions of data recording and
Bluetooth data reading.
1) Data recording: the meter can save 1000 pieces of
data records. Long-press REC/RANG key to enable
the meter to record data. The REC indicator on LCD
will be on, and the meter will store the current
measurement data at the rate of 3 times/s. Long-press
REC key again to exit the data recording function. The
meter also can exit the data recording function when
the 1000 pieces of data are recorded or a key operation
or gear switching operation is performed.
2) Data reading: the meter cannot support the direct
reading of stored data, and it only support the reading of
the stored data with the Bluetooth function through a
specific APP on the mobile phone.
4.9 ▼function
Short-press LINK/REL/▼ in the harmonic measurement
interface at KW and W gears to scroll down, and to switch
between the 1st harmonic and 20th harmonic. At the KW
and W gears, short-press the function key in the
maximum/minimum value measurement interface to
scroll down, and switch and display the
maximum/minimum value.

4.10 ▲function
Short-press in the harmonic measurement interface at
KW and W gears to scroll up, and to switch between the
1st harmonic and 20th harmonic. At the KW and W gears,
short-press the function key in the maximum/minimum
value measurement interface to scroll up, and switch and
display the maximum/minimum value.
4.11 INRUSH measurement
Long-press "Hz/%/INRUSH/▲" for more than 2 s at AC
current gear to enterthe inrush measurement state.
4.12 Back-light and clamp lighting
1) During measurement, if the ambient light is too dim to
read, press the "B.L/HOLD" for more than 2 s to turn on
the back-light, and the back-light will be off 20 s later.
2) In this period, press the "B.L/HOLD" key for 2 s to turn
off the back-light.
3) Turn on the back-light of the meter at the current gear,
and the clamp lamp will be on at the same time.
The luminous object of the back-light is LED with high
working current.
Although this meter is set with timing circuit (with time
of 30 s), the service life of battery will be shortened
with frequent use of back-light.
Therefore, you shall minimize the use of back-light as
far as possible under the unnecessary conditions.
Note:
When the battery voltage ≤ 7.2 V, the display will display
the symbol of " "(under-voltage). However,
if the back-light is used, when the battery voltage ≥ 7.2 V,
the battery voltage is reduced due to high working current,
the display may display the symbol " "(when the
symbol of " " is displayed, the measurement accuracy
cannot be guaranteed). Under such circumstance, the
battery will not be replaced until the symbol " " is
displayed without back-light.
4.13 Automatic shutdown
1) After startup, in case of no operation within 30 minutes,
the meter will enter the dormant state and shut down
automatically for saving electric energy. There will be
voice prompt (a prolonged blast) from the buzzer 1
minute before shutdown, and then the meter will shut
down automatically.
2) After shutdown, press FUNC key and the meter will
resume operation.
3) If the "B.L/HOLD" key is pressed during startup, the
function of automatic shutdown will cancel automatically.
4.14. Measurement preparation
1) Turn the change-over switch to power on the meter. If
the battery is in under-voltage state (the voltage ≤ 7.2 V),
the display will display the symbol " ", and then the
battery shall be replaced.
2) " " means that the input voltage or current shall not
be greater than the indicated value in order to prevent
the internal circuit from damage.
3) Turn the change-over switch to the required
measurement function and range.
4) For wiring, connect the public testing line at first and
then connect the energized testing line. For
disconnecting,remove the energized testing line at first.
24 25

26 27
4.15 AC current measurement
WARNING
Electric shock.
Remove the probe from the meter before measuring
with the current clamp.
1) Turn the change-over switch to AC current gear. At this
time, the meter is in AC current measurement state, and
then the suitable range shall be selected.
2) Hold the trigger, and open the clamp to clamp one
conductor of measured circuits.
3) Read the current value from LCD display.
Note:
1) If two or more circuits of the measured circuits are
clamped, the measurement result will be not correct.
2) In order to acquire the accurate reading, the measured
conductor shall be in the center of clamp as far as
possible.
3) " " means that the maximum AC input current is
1000 A.
4) When the reading is greater than 600.1 A at 60 A/600 A,
there will be the alarm sound "beep" from the meter.
When the reading is greater than 620 A rms, the ACA will
display overload.
5) When the reading is greater than 1001 A at 1,000 A,
there will be the alarm sound "beep" from the meter.
When the reading is greater than 1,100 A rms, the ACA
will display overload.
Figure 1 Schematic Diagram for Current Measurement at AC Gear

this case, the meter is in the DC voltage measurement
state. If the AC voltage shall be measured, press the
FUNC key and the meter will enter the AC voltage
measurement state.
3) Connect the probe to both ends of voltage source or
load to conduct measurement.
4) Read the voltage value from LCD.
Note:
1) The auto range will be unavailable under the relative
measurement mode.
2) " " means that the maximum input voltage is 750 V
AC or 1000 V DC.
3) There will be the alarm sound "beep" from the meter,
when the measured reading of the meter is greater than
600 V rms ACV.
When the reading is greater than 750 V rms ACV, the
meter will display overload.
4) There will be the alarm sound "beep" from the meter,
when the measured reading of the meter is greater than
1000 V rms DCV.
When the reading is greater than 1100V rms, the DCV
will display overload.
4.16. Voltage measurement
WARNING
Electric shock.
Pay special attention to high voltage measurement to
avoid electric shock.
Do not input the voltage with the effective value
greater than AC 750.
1) Plug the black probe into COM jack, plug the red probe
into INPUT jack, and select the suitablerange.
2) Turn the change-over switch to AC/DC voltage gear. In
Figure 2: Schematic Diagram for AC Voltage Measurement at
AC/DC Voltage Gear
28 29

30 31
4.17 Measuring frequency and duty ratio
1) Frequency measurement with clamp (at
current gear):
WARNING
Electric shock.
Remove the probe from the meter before measuring
with the current clamp.
(1) Turn the change-over switch to AC current gear.
(2) Hold the trigger, and open the clamp to clamp one
conductor of measured circuits.
(3) Press the "Hz/%INRUSH/▲"button shortly to switch
into the status of frequency measurement.
(4) Read the frequency value from LCD display.
(5) Press "Hz/%INRUSH/▲"again to enter the status of
duty ratio measurement.
Note:
(1) If two or more circuits of the measured circuits are
clamped, the measurement result will be not correct.
(2)The measurement range of frequency is 10 Hz ~ 1 kHz.
If the measured frequency is less than 10 Hz, the
frequency greater than 10 kHz might be measured, but
the accuracy of measurement cannot be guaranteed.
(3) The measurement range of duty ratio is 10 ~ 95%.
(4) The maximum input current of " " is 1000A AC
(effective value).
2) At voltage gear:
WARNING
Electric shock.
Pay special attention to high voltage measurement to
avoid electric shock.
Do not input the voltage with effective value greater
than AC 750.
(1) Insert the black probe into COM jack, and insert the red
probe into INPUT jack.
(2) Turn the change-over switch to AC/DC voltage gear,
press FUNC to enter the status of AC voltage
measurement.
(3) Press the "Hz/%INRUSH/▲"button to switch into the
frequency measurement state.
(4) Connect the probe to both ends of signal source or
load to conduct measurement.
(5) Read on the LCD.
(6) Press "Hz/%INRUSH/▲"again to enter the status of
duty ratio measurement.
Note:
(1) The measurement range of frequency is 10 Hz ~ 10kHz.
If the measured frequency is less than 10 Hz, the LCD
will display "00.0", the frequency less than 10 kHz
might be measured, but the accuracy of measurement
cannot be guaranteed.
(2) The measurement range of duty ratio is 10 ~ 95%.
(3) The maximum input voltage of " " is 750 V AC
(effective value).

32 33
3) At HZ/DUTY gear:
WARNING
Electric shock.
Pay special attention to high voltage measurement to
avoid electric shock.
Do not input the voltage with effective value greater
than AC 750 V.
(1) Insert the black probe into COM jack, and insert the red
probe into INPUT jack.
(2) Turn the change-over switch to HZ% gear.
(3) Connect the probe to both ends of signal source or load
to conduct measurement.
(4) Read on the LCD.
(5) Press "Hz/%INRUSH/▲"again to enter the status of
duty ratio measurement.
Note:
The measurement range of frequency is 10 Hz ~ 9.999
MHz, if the measured frequency less than 10 Hz, the LCD
will display "00.0"; the frequency greater than 9.999 MHz
might be measured, but the accuracy of measurement
cannot be guaranteed.
Figure 3: Schematic Diagram for Frequency Measurement at
HZ% Gear

34 35
4.18 Resistance measurement
WARNING
Electric shock.
When measuring the impedance on the circuit, the
circuit power should be disconnected, and the
capacitor in the circuit should be completely
discharged.
1) Insert the black probe into COM jack, and insert the red
probe into INPUT jack.
2) Place the change-over switch on the gear, and set
the meter in the status of resistance measurement.
3) Connect the probes to both ends of the measured
resistor or the circuit for measurement.
4) Read on the LCD.
Note:
1) When the input is open-circuited, the LCD will display
"0L" for over range.
2) If the resistance of measured resistor is greater than
1 MΩ, the reading of the meter might be stable after a
few seconds, and it is common for the high resistance
readings.
Figure 4 Schematic Diagram for Resistance Measurement at
Gear