Extech Extech MG300 Manual

User's Guide

Wireless TRMS Multimeter and
Insulation Tester

Model MG300

99 Washington Street
Melrose, MA 02176

Phone [phone]
Toll Free 1-800-517-8431

Visit us at www.TestEquipmentDepot.com

Introduction

Congratulations on your purchase of the MG300 True RMS MultiMeter Insulation Resistance Tester.
This meter measures AC/DC Voltage, AC/DC Current, Resistance, Capacitance, Frequency
(electrical & electronic), Duty Cycle, Diode Test, Insulation Resistance, and Continuity plus
Thermocouple Temperature. The MG300 can store and recall measurement data and features a
waterproof, rugged design for heavy duty use. This meter can transmit data wirelessly when linked to
a PC. Proper use and care of this meter will provide many years of reliable service.

Safety

This symbol adjacent to another symbol, terminal or operating device indicates
that the operator must refer to an explanation in the Operating Instructions to
avoid personal injury or damage to the meter.

WARNING

CAUTION

MAX
1000V

PER IEC1010 OVERVOLTAGE INSTALLATION CATEGORY

OVERVOLTAGE CATEGORY I

Equipment of OVERVOLTAGE CATEGORY I is equipment for connection to circuits in which
measures are taken to limit the transient overvoltages to an appropriate low level.

Note – Examples include protected electronic circuits.

OVERVOLTAGE CATEGORY II

Equipment of OVERVOLTAGE CATEGORY II is energy-consuming equipment to be supplied from
the fixed installation.

Note – Examples include household, office, and laboratory appliances.

OVERVOLTAGE CATEGORY III

Equipment of OVERVOLTAGE CATEGORY III is equipment in fixed installations.

Note – Examples include switches in the fixed installation and some equipment for industrial use with

permanent connection to the fixed installation.

OVERVOLTAGE CATEGORY IV

Equipment of OVERVOLTAGE CATEGORY IV is for use at the origin of the installation.

Note – Examples include electricity meters and primary over-current protection equipment

This WARNING symbol indicates a potentially hazardous situation, which if not
avoided, could result in death or serious injury.

This CAUTION symbol indicates a potentially hazardous situation, which if not
avoided, may result damage to the product.

This symbol advises the user that the terminal(s) so marked must not be
connected to a circuit point at which the voltage with respect to earth ground
exceeds (in this case) 1000 VAC or VDC.

This symbol adjacent to one or more terminals identifies them as being associated
with ranges that may, in normal use, be subjected to particularly hazardous
voltages. For maximum safety, the meter and its test leads should not be handled
when these terminals are energized.

This symbol indicates that a device is protected throughout by double insulation or
reinforced insulation.

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SAFETY INSTRUCTIONS

This meter has been designed for safe use, but must be operated with caution. The rules listed below
must be carefully followed for safe operation.

1. NEVER apply voltage or current to the meter that exceeds the specified maximum:

Input Protection Limits

Function Maximum Input
V DC or V AC 1000VDC/AC rms
mA AC/DC 500mA 1000V fast acting fuse
A AC/DC

Frequency, Resistance, Capacitance,
Duty Cycle, Diode Test, Continuity

Temperature 1000VDC/AC rms
Surge Protection: 8kV peak per IEC 61010

2. USE EXTREME CAUTION when working with high voltages.

3. DO NOT measure voltage if the voltage on the "COM" input jack exceeds 1000V above earth
ground.

4. NEVER connect the meter leads across a voltage source while the function switch is in the
current, resistance, or diode mode. Doing so can damage the meter.

5. ALWAYS discharge filter capacitors in power supplies and disconnect the power when making
resistance or diode tests.

10A 1000V fast acting fuse (20A for 30 seconds max
every 15 minutes)

1000VDC/AC rms

6. ALWAYS turn off the power and disconnect the test leads before opening the covers to replace
the fuse or batteries.

7. NEVER operate the meter unless the back cover and the battery and fuse covers are in place
and fastened securely.

8. If the equipment is used in a manner not specified by the manufacturer, the protection provided
by the equipment may be impaired.

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Controls and Jacks

1. 40,000 count LCD display

2. MAX/MIN ( - ) button

3. STORE (<RECALL) button

4. RANGE(SETUP) button

5. INSULATION TEST button

6. MODE button

7. Function switch

8. 10A input jack

9. mA, µA, Insulation (-) jack

10. HOLD (PEAKHOLD>) button

11. REL (+) button

12. EXIT (AC+DC) button

13.

Backlight button

14. Positive and Insulation (+) input jack

15. COM input jack
Note: Tilt stand and battery compartment are on rear of unit.

1

2

3

4

5

6

7

8
9

Symbols and Annunciators

•))) Continuity
Diode test

Battery status
n nano (10
µ micro (10
m milli (10
A Amps
k kilo (10
F Farads (capacitance)

M mega (10
 Ohms PEAK Peak Hold
Hz Hertz (frequency) V Volts
% Percent (duty ratio)
AC Alternating current AUTO Autoranging
DC Direct current HOLD Display hold

ºF Degrees Fahrenheit ºC Degrees Celsius
MAX Maximum MIN Minimum
No. Serial number S second
SET Setup parameter AC +DC Alternating current + Direct current
TRMS True RMS STO Store
RCL Recall AUTO Auto Range

-9

) (capacitance) 

-6

) (amps, cap)

-3

) (volts, amps)

3

) (ohms)

6

) (ohms) RF transmitter active

Relative

Auto Power off enabled Backlight

Auxiliary Displays

4 MG300-EN V2.0 4/11

11

10

12
13

14
15

Operating Instructions

WARNING: Risk of electrocution. High-voltage circuits, both AC and DC, are very dangerous and
should be measured with great care.

1. ALWAYS turn the function switch to the OFF position when the meter is not in use.

2. If “OL” appears in the display during a measurement, the value exceeds the range you have
selected. Change to a higher range.

DC VOLTAGE MEASUREMENTS

CAUTION: Do not measure DC voltages if a motor on the circuit is being switched ON or OFF.

Large voltage surges may occur that can damage the meter.

1. Set the function switch to the VDC position.

2. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive V jack.

3. Touch the black test probe tip to the negative side of the circuit.
Touch the red test probe tip to the positive side of the circuit.

4. Read the voltage in the display.

AC VOLTAGE (FREQUENCY, DUTY CYCLE) MEASUREMENTS

WARNING: Risk of Electrocution. The probe tips may not be long enough to contact the live parts

inside some 240V outlets for appliances because the contacts are recessed deep in the outlets. As
a result, the reading may show 0 volts when the outlet actually has voltage on it. Make sure the
probe tips are touching the metal contacts inside the outlet before assuming that no voltage is
present.

CAUTION: Do not measure AC voltages if a motor on the circuit is being switched ON or OFF.
Large voltage surges may occur that can damage the meter.

1. Set the function switch to the VAC/Hz/% position.

2. Insert the black test lead banana plug into the negative COM jack.
Insert red test lead banana plug into the positive V jack.

3. Touch the black test probe tip to the neutral side of the circuit.
Touch the red test probe tip to the “hot” side of the circuit.

4. Read the voltage in the main display and the frequency in the right
auxiliary display

5. Press and hold the MODE button for 2 seconds to indicate “Hz”.

6. Read the frequency in the main display.

7. Press the MODE button again to indicate “%”.

8. Read the % of duty cycle in the main display.

9. Press EXIT to return to AC volts display

10. With ACV in the main display, press and hold EXIT for 2 seconds to measure
AC+DC.

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mV VOLTAGE MEASUREMENTS

CAUTION: Do not measure mV voltages if a motor on the circuit is being switched ON or OFF.

Large voltage surges may occur that can damage the meter.

1. Set the function switch to the mV position.

2. Press the MODE button to indicate “DC” or “AC”

3. In AC mode, press and hold EXIT for two seconds to select ”AC+DC”

4. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive V jack.

5. Touch the black test probe tip to the negative side of the circuit. Touch the red
test probe tip to the positive side of the circuit.

6. Read the mV voltage in the main display.

DC CURRENT MEASUREMENTS

CAUTION: Do not make 20A current measurements for longer than 30 seconds. Exceeding 30

seconds may cause damage to the meter and/or the test leads.

1. Insert the black test lead banana plug into the negative COM jack.

2. For current measurements up to 4000µA DC, set the function switch to the
µA position and insert the red test lead banana plug into the µA/mA jack.

3. For current measurements up to 400mA DC, set the function switch to the
mA position and insert the red test lead banana plug into the µA/mA jack.

4. For current measurements up to 20A DC, set the function switch to the
10A/HZ/% position and insert the red test lead banana plug into the 10A jack.

5. Press the MODE button to indicate “DC” on the display.

6. Remove power from the circuit under test, then open up the circuit at the
point where you wish to measure current.

7. Touch the black test probe tip to the negative side of the circuit.
Touch the red test probe tip to the positive side of the circuit.

8. Apply power to the circuit.

9. Read the current in the display.

AC+DC

In the VAC, mV(AC), 10A(AC), mA(AC) and uA(AC) measurement modes, press the EXIT button
for 2 seconds to enter AC+DC test mode. The LCD shows the AC+DC icon. Press EXIT to exit this
mode.

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AC CURRENT (FREQUENCY, DUTY CYCLE) MEASUREMENTS

CAUTION: Do not make 20A current measurements for longer than 30 seconds. Exceeding 30

seconds may cause damage to the meter and/or the test leads.

1. Insert the black test lead banana plug into the negative COM jack.

2. For current measurements up to 4000µA AC, set the function switch to the
µA position and insert the red test lead banana plug into the µA/mA jack.

3. For current measurements up to 400mA AC, set the function switch to the
mA position and insert the red test lead banana plug into the µA/mA jack.

4. For current measurements up to 20A AC, set the function switch to the
10A/HZ/% position and insert the red test lead banana plug into the 10A
jack.

5. Press the MODE button to indicate “AC” on the display.

6. Press and hold EXIT for 2 seconds to select AC+DC.

7. Remove power from the circuit under test, then open up the circuit at the
point where you wish to measure current.

8. Touch the black test probe tip to the neutral side of the circuit.
Touch the red test probe tip to the “hot” side of the circuit.

9. Apply power to the circuit.

10. Read the current in the display.

11. In the 10A range:
a) Frequency is displayed in the upper right display.
b) Press and hold the MODE button to display “Hz” in the main display.
c) Momentarily press the MODE button again to display “%” in the main display.

12. Press and hold the MODE button to return to current measurement.

RESISTANCE MEASUREMENTS

WARNING: To avoid electric shock, disconnect power to the unit under test and discharge all

capacitors before taking any resistance measurements. Remove the batteries and unplug the line
cords.

1. Set the function switch to the ΩCAP position.

2. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive  jack.

3. Press the MODE button to indicate “”on the display.

4. Touch the test probe tips across the circuit or part under test. It is best to
disconnect one side of the part under test so the rest of the circuit will not
interfere with the resistance reading.

5. Read the resistance in the display.

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CONTINUITY CHECK

WARNING: To avoid electric shock, never measure continuity on circuits or wires that have

voltage on them.

1. Set the function switch to the Ω CAP position.

2. Insert the black lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive  jack.

3. Press the MODE button to indicate“ ” and “Ω” on the display

4. Touch the test probe tips to the circuit or wire you wish to check.

5. If the resistance is less than approximately 35, the audible signal will sound.
If the circuit is open, the display will indicate “OL”.

DIODE TEST

1. Set the function switch to the Ω CAP position.

2. Insert the black test lead banana plug into the negative COM jack and the red
test lead banana plug into the positive V jack.

3. Press the MODE button to indicate “ ” and “V” on the display.

4. Touch the test probes to the diode under test. Forward voltage will typically
indicate 0.400 to 0.700V. Reverse voltage will indicate “OL”. Shorted devices
will indicate near 0V and an open device will indicate “OL” in both polarities.

CAPACITANCE MEASUREMENTS

WARNING: To avoid electric shock, disconnect power to the unit under test and discharge all

capacitors before taking any capacitance measurements. Remove the batteries and unplug the
line cords.

1. Set the rotary function switch to the Ω CAP position.

2. Insert the black test lead banana plug into the negative COM jack.

3. Insert the red test lead banana plug into the positive V jack.

4. Press the MODE button to indicate “F”

5. Touch the test leads to the capacitor to be tested.

6. Read the capacitance value in the display

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TEMPERATURE MEASUREMENTS

1. Set the function switch to the Temp position.

2. Insert the Temperature Probe into the input jacks, making sure to
observe the correct polarity.

3. Press the MODE button to indicate “ºF” or “ºC”

4. Touch the Temperature Probe head to the part whose temperature you
wish to measure. Touch the part under test with the probe until the
reading stabilizes.

5. Read the temperature in the display.

Note: The temperature probe is fitted with a type K mini connector. A mini

connector to banana connector adaptor is supplied for connection to the input banana jacks.

FREQUENCY (DUTY CYCLE) MEASUREMENTS (ELECTRONIC)

1. Set the rotary function switch to the Hz/% position.

2. Insert the black lead banana plug into the negative COM jack and the red test
lead banana plug into the positive Hz jack.

3. Touch the test probe tips to the circuit under test.

4. Read the frequency on the display.

5. Press the MODE button to indicate “%”.

6. Read the % duty cycle in the display.

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% 4 – 20mA MEASUREMENTS

1. Set up and connect the meter as described for DC mA measurements.

2. Set the rotary function switch to the 4-20mA% position.

3. The meter will display loop current as a % with 0mA=-25%, 4mA=0%, 20mA=100%, and
24mA=125%.

INSULATION RESISTANCE MEASUREMENTS

Note: Disconnect the unit under test from all power sources and isolate it from any stray

resistance.

1. Set the rotary function switch to the INSULATION position

2. Press the RANGE button to select the test voltage as indicated on the top left display.

3. Connect the red test lead to the meter’s INSULATION ( + ) jack and the black test lead to the
INSULATION ( - ) jack. Connect the probe end of the test leads to the circuit under test.

4. Press and hold the TEST button to test (alternatively, press and hold the LOCK key until the
display shows LOCK and then momentarily press the TEST button to start a hands free test).

Note: If the circuit under test is live and has a voltage potential (AC/DC) over 30V, the meter it
will not test (the display will show “>30V”, the
the circuit under test is not live or if its voltage is less than 30V, the meter will begin applying

symbol will flash, and the buzzer will sound). If

high-voltage to the circuit under test.

5. The primary display and the analog bargraph will show the insulation resistance in MΩ.

6. The test voltage (VDC) value will be indicated in the right-most auxiliary display, the

symbol

will flash and the caution buzzer will sound.

7. Release the TEST button to stop the test (to stop a hands free LOCK test, press and hold the
release button for 2 seconds). The high voltage will switch off and the resistance values
indicated in the primary display hold.

8. Subsequently, the meter will internally discharge the balance of the insulation test voltage.

Note: Turning the function switch to another test position or pressing the EXIT button will abort an

Insulation resistance test.

RANGE

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AUTORANGING/MANUAL RANGE SELECTION

When the meter is first turned on, it automatically enters the AUTO RANGE mode. This
automatically selects the best range for the measurements being made and is generally the best
mode for most measurements. For measurement situations requiring that a range be manually
selected, perform the following:

1. Press the RANGE key. The “AUTO” display indicator will turn off.

2. Press the RANGE key to step through the available ranges.

3. To exit the MANUAL RANGE mode, press EXIT

Note: MANUAL RANGE is not available for the Temperature functions.

MAX/MIN

1. Press the MAX/MIN key to activate the MAX/MIN recording mode. The display icon "MAX" will
appear. The meter’s left-most auxiliary display will show and hold the maximum reading,
updating only when a new “MAX” occurs. The display icon "MIN" will then appear. The right­most auxiliary display will show and hold the minimum reading, updating only when a new
“MIN” occurs.

2. To exit MAX/MIN mode press EXIT.

RELATIVE MODE

The relative measurement mode displays readings that are relative to a stored reference value. A
reference voltage, current, etc. can be stored and measurements are made in comparison to that
value. The displayed value is the difference between the reference value and the measured value.

1. Perform the measurement as described in the operating instructions.

2. Press the REL button to store a reference reading; the "▲" indicator will appear on the display.

3. The auxiliary display on the right displays the initial reading (the stored value).

4. The auxiliary display on the left displays the actual currently measured value.

5. The main display shows the Relative value (measured value minus the stored value).

AC+DC

In the VAC, mV(AC), 10A(AC), mA(AC) and uA(AC) measurement modes, press the EXIT button
for 2 seconds to enter AC+DC test mode. The LCD shows the AC+DC icon. Press EXIT to exit this
mode.

11 MG300-EN V2.0 4/11

DISPLAY BACKLIGHT

Press the
time has expired. Press the EXIT button to exit the backlight on mode.

HOLD

The hold function freezes the reading in the display. Press the HOLD key momentarily to activate or
to exit the HOLD function.

PEAK HOLD

The Peak Hold function captures the peak AC or DC voltage or current. The meter can capture
negative or positive readings as fast as 1 millisecond in duration. Momentarily press the PEAK
button, “PEAK” and “MAX” will display in the left auxiliary display. MIN” will display in right auxiliary
display. The meter will update the dispay each time a greater value occurs. Press the EXIT button
to exit the PEAK HOLD mode. Auto Power Off feature will be disabled automatically in this mode.

DATA STORAGE

1. Set the function switch to the measurement function desired.

2. Press the STORE button to access the recording interval time set up function.

3. The auxiliary display on the left indicates 0000 S, which is the recording sample rate; use the +

4. Set the sample rate to 0000 S for manual recording. In this mode, each press of the STORE

5. Set the sample rate (from 1 to 255 S) for automatic recording. In this mode, pressing the

6. The auxiliary display on the left indicates the current storage location (0000 to 9999). New

7. Press and hold the STORE button for 2 seconds to enter the RECALL mode or press EXIT to

DATA STORAGE RECALL

1. Press and hold the STORE button for two seconds (if not already done as instructed in step 7

2. The auxiliary display on the left will show XXXX (current storage location). The auxiliary display

3. Use the + and - buttons to navigate the storage locations. The value for the selected location is

4. Press the EXIT button to end the recall session.

CLEAR ALL DATA

1. From the OFF position, press and hold the RANGE button while turning the function switch to

2. Release the RANGE button. The memory has been cleared.

key to switch the backlight on. The backlight will automatically switch off after the SET

& - buttons to select the desired sample rate (0 to 255 seconds)

button will save one measurement reading.

STORE button will start data recording at the programmed sample rate.

measurements will begin storing into the next available location.

return to the normal operating mode.

in the above procedure) to enter the RECALL function.

on the right will show XXXX (number of storage locations used).

indicated in the main display.

any on position

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PC WIRELESS COMMUNICATION

1. Install and launch the PC software (refer to the HELP utility contained in the software for more
details)

2. Press and Hold the backlight/USB button for two seconds to enter RF wireless transmit mode

3. The RF icon

will appear on the display

4. When communication is established, the RF icon on the display will blink and the LED indicator
on the receiver will blink

5. Once per second, the data will be displayed on the PC screen (plotted on the graph and
inserted to the data list)

6. Hold the backlight button for two seconds to exit the RF wireless transmit mode

SENDING STORED DATA TO THE PC

1. Launch the PC software

2. Press the STORE button for two seconds to enter into data RECALL function.

3. Press the HOLD button for two seconds. The RF transmit icon will flash while the stored data is
sent to the PC

NOTE: Refer to the HELP utility included in the supplied software program for in-depth
software instructions.

SETUP

1. Press and Hold the RANGE/SETUP button for two seconds to enter the SET function. The first
of five settable functions will appear.

2. Press the RANGE button to step through the functions
a: Alarm High limit buzzer alarm OFF or Value
b: Alarm Low limit buzzer alarm OFF or Value
c: Auto power off time OFF, 10 to 30 sec
d: Button beeper ON/OFF
e : Back light time OFF, 10 to 30 sec

3. Use the +, - ,◄ and ► buttons to select and change conditions and digits.

4. Press the RANGE/SETUP button until the meter returns to the normal display to exit this mode.

ALARM L IMITS

1. Press and Hold the SETUP button for two seconds to enter the High Limit function.

2. Press the ► button to select a digit for adjustment

3. Press the + or – button to adjust the value of the digit

4. Press the

◄ button to turn the alarm OFF.

5. Press the SETUP button and repeat the procedure to set the low limit

6. Press the SETUP button to step through the other functions and return to the normal operating
mode.

7. The meter will “beep” if the measured value is greater than the high limit or lower than the low
limit.

LOW BATTERY INDICATION

When the

icon appears in the display, the battery should be replaced.

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Maintenance

WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before
removing the back cover or the battery or fuse covers.

WARNING: To avoid electric shock, do not operate your meter until the battery and fuse covers are
in place and fastened securely.

This MultiMeter is designed to provide years of dependable service, if the following care instructions
are performed:

1. KEEP THE METER DRY. If it gets wet, wipe it off.

2. USE AND STORE THE METER IN NORMAL TEMPERATURES. Temperature extremes can
shorten the life of the electronic parts and distort or melt plastic parts.

3. HANDLE THE METER GENTLY AND CAREFULLY. Dropping it can damage the electronic parts
or the case.

4. KEEP THE METER CLEAN. Wipe the case occasionally with a damp cloth. DO NOT use
chemicals, cleaning solvents, or detergents.

5. USE ONLY FRESH BATTERIES OF THE RECOMMENDED SIZE AND TYPE. Remove old or
weak batteries so they do not leak and damage the unit.

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.

BATTERY INSTALLATION

WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before

removing the battery cover.

1. Turn power off and disconnect the test leads from the meter.

2. Open the rear battery cover by removing four screws using a Phillips head screwdriver.

3. Insert the battery into battery holder, observing the correct polarity.

4. Put the battery cover back in place. Secure with the screws.

You, as the end user, are legally bound (EU Battery ordinance) to return all used
batteries, disposal in the household garbage is prohibited! You can hand over your
used batteries / accumulators at collection points in your community or wherever batteries
/ accumulators are sold!

Disposal: Follow the valid legal stipulations in res pect of the disposal of the device at the
end of its lifecycle

WARNING: To avoid electric shock, do not operate your meter until the battery cover is in place and
fastened securely.

14 MG300-EN V2.0 4/11

REPLACING THE FUSES

WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before

removing the meter cover.

1. Disconnect the test leads from the meter.

2. To replace the 500mA fuse only, remove the battery cover (four screws); the 500mA fuse will be
visible and accessible.

3. To replace the 10A fuse, remove the six screws securing the rear cover and remove the rear
cover.

4. Gently remove the old fuses and install the new fuses into the holders.

5. Always use a fuse of the proper size and value (0.5A/1000V fast blow for the 400mA range [SIBA
70-172-40], 10A/1000V fast blow for the 20A range [SIBA 50-199-06]).

6. Replace and secure the rear cover, battery and battery cover.

WARNING: To avoid electric shock, do not operate your meter until the fuse cover is in place and
fastened securely.

FCC Part 15

This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment generates, uses and can
radiate radio frequency energy and, if not installed and used in accordance with the instructions,
may cause harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the interference by one or more of the following
measures:
—Reorient or relocate the receiving antenna.
—Increase the separation between the equipment and receiver.
—Connect the equipment into an outlet on a circuit different from that to which the receiver is

connected.
—Consult the dealer or an experienced radio/TV technician for help.
Warning: Changes or modifications not expressly approved by the party responsible for compliance
could void the user's authority to operate the equipment.

15 MG300-EN V2.0 4/11

Specifications

Function Range Resolution Accuracy
DC Voltage

AC Voltage
(AC+DC)
50 to 1000Hz

DC Current

AC Current
(AC+DC)
50 to 1000Hz

NOTE: Accuracy is stated at 65oF to 83oF (18oC to 28oC) and less than 75% RH.

400mV 0.01mV
4V 0.0001V
40V 0.001V
400V 0.01V
1000V 0.1V
400mV 0.1mV
4V 0.001V
40V 0.01V
400V 0.1V
1000V 1V
All AC voltage ranges are specified from 5% of range to 100% of range
400A 0.01A
4000A 0.1A
40mA 0.001mA
400mA 0.01mA
10A 0.001A
(20A: 30 sec max with reduced accuracy)
400A 0.1A
4000A 1A
40mA 0.01mA
400mA 0.1mA
10A 0.01A

(20A: 30 sec max with reduced accuracy)
All AC voltage ranges are specified from 5% of range to 100% of range

(0.06% reading + 4 digits)

(0.1% reading + 5 digits)
(1.0% reading + 7 digits)

(1.0% reading +5 digits)

(1.0% reading + 3 digits)

(1.5% reading +7 digits)

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Function Range Resolution Accuracy

Resistance

Capacitance

Frequency
(electronic)

Frequency
(electrical)

Duty Cycle

Temp
(type-K)

Note: Accuracy specifications consist of two elements:

 (% reading) – This is the accuracy of the measurement circuit.
 (+ digits) – This is the accuracy of the analog to digital converter.

400 0.01 (0.3% reading + 9 digits)
4k 0.0001k
40k 0.001k
400k 0.01k
4M 0.0001M
40M 0.001M (2.0% reading + 10 digits)
40nF 0.001nF
400nF 0.01nF
4F 0.0001F
40F 0.001F
400F 0.01F
4mF 0.0001mF
40mF 0.001mF
40Hz 0.001Hz
400Hz 0.01Hz
4kHz 0.0001kHz
40kHz 0.001kHz
400kHz 0.01kHz
4MHz 0.0001MHz
40MHz 0.001MHz
100MHz 0.01MHz Not specified
Sensitivity: 0.8V rms min. @ 20% to 80% duty cycle and <100kHz; 5Vrms min @

20% to 80% duty cycle and > 100kHz.

40.00HZ-4KHz 0.01HZ to

0.001KHz

Sensitivity:5Vrms

0.1 to 99.90% 0.01%
Pulse width: 100µs - 100ms, Frequency: 5Hz to 150kHz

-58 to 1832F 0.1F

-50 to 1000C 0.1C

-25 to 125% 0.01% ±50 digits 4-20mA%

0mA=-25%, 4mA=0%, 20mA=100%, 24mA=125%

(0.3% reading + 4 digits)

(3.5% reading + 40 digits)

(3.5% reading + 10 digits)

(5% reading + 10 digits)

(0.1% reading + 1 digits)

(0.5% reading)

(1.2% reading + 2 digits)

(1.0% reading + 4.5°F)

(1.0% reading + 2.5°C)

(probe accuracy not included)

17 MG300-EN V2.0 4/11

Meg OHMS

Terminal Voltage Range Resolution Accuracy Test current Short circuit

current

125V (0%~+10%)

250V (0%~+10%)

500V (0%~+10%)

1000V
(0%~+10%)

Note: Accuracy specifications consist of two elements:

 (% reading) – This is the accuracy of the measurement circuit.
 (+ digits) – This is the accuracy of the analog to digital converter.

0.125~4.000 MΩ 0.001MΩ +(2%+10)

4.001~40.00 MΩ 0.01MΩ +(2%+10)

40.01~400.0 MΩ 0.1MΩ +(4%+5)

400.1~4000 MΩ 1MΩ +

0.250~4.000 MΩ 0.001MΩ +(2%+10)

4.001~40.00 MΩ 0.01MΩ +(2%+10)

40.01~400.0 MΩ 0.1MΩ +(3%+5)

400.1~4000 MΩ 1MΩ +

0.500~4.000 MΩ 0.001MΩ +(2%+10)

4.001~40.00 MΩ 0.01MΩ +(2%+10)

40.01~400.0 MΩ 0.1MΩ +(2%+5)

400.1~4000 MΩ 1MΩ +

1.000~4.000 MΩ 0.001MΩ +(3%+10)

4.001~40.00 MΩ 0.01MΩ +(2%+10)

40.01~400.0 MΩ 0.1MΩ +(2%+5)

400.1~4000 MΩ 1MΩ +

(5%+5)

(4%+5)

(4%+5)

(4%+5)

1mA @ load

125kΩ

1mA @ load

250kΩ

1mA @ load

500kΩ

1mA @ load

1MΩ

≤1mA

≤1mA

≤1mA

≤1mA

18 MG300-EN V2.0 4/11

Enclosure Double molded, waterproof (IP67)
Shock (Drop Test) 6.5 feet (2 meters)
Diode Test Test current 0.9mA maximum, open circuit voltage 2.8V DC typical
Storage capacity 8000 records
RF transmit distance 10 meters (approx)
Transmitter Frequency 915MHz
Continuity Check Audible signal will sound if the resistance is less than 35 (approx.), test

current <0.35mA

Peak Captures peaks >1ms
Temperature Sensor Requires type K thermocouple
Input Impedance >10MΩ VDC & >9MΩ VAC
AC Response True rms
ACV Bandwidth 50Hz to 1000Hz
Crest Factor ≤3 at full scale up to 500V, decreasing linearly to ≤1.5 at 1000V
Display 40,000 count, backlit, liquid-crystal display with bargraph
Overrange indication “OL” is displayed
Auto Power Off 15 minutes (approximately) with disable feature
Polarity Automatic (no indication for positive); Minus (-) sign for negative
Measurement Rate 2 times per second, nominal

Low Battery Indication “

” is displayed if battery voltage drops below operating voltage
Battery Six (6) 1.5V ‘AA’ batteries
Fuses mA, µA ranges; 0.5A/1000V ceramic fast blow (SIBA 70-172-40)

A range; 10A/1000V ceramic fast blow (SIBA 50-199-06)

Operating Temperature 41ºF to 104ºF (5ºC to 40ºC)
Storage Temperature -4

o

F to 140oF (-20oC to 60oC)

Operating Humidity Max 80% up to 87ºF (31ºC) decreasing linearly to 50% at 104ºF (40ºC)
Storage Humidity <80%
Operating Altitude 7000ft (2000meters) maximum
Weight 20.5 oz. (582g)
Size 7.8” x 3.6” x 1.9” (200 x 92 x 50mm)
Safety This meter is intended for origin of installation use and protected, against

the users, by double insulation per EN61010-1 and IEC61010-1 2

nd

Edition

(2001) to Category IV 600V and Category III 1000V; Pollution Degree 2.

19 MG300-EN V2.0 4/11