Congratulations on your purchase of the Extech EX410A Multimeter. This meter measures AC/DC
Voltage, AC/DC Current, Resistance, Diode Test, and Continuity plus Thermocouple Temperature. This
device is shipped fully tested and calibrated and, with proper use, will provide years of reliable service.
Please visit our website (www.extech.com) to check for the latest version of this User Guide, Product
Updates, additional user manual languages, and Customer Support.
Safety
International Safety Symbols
This symbol, adjacent to another symbol or terminal, indicates the user must refer
to the manual for further information.
This symbol, adjacent to a terminal, indicates that, under normal use, hazardous
voltages may be present
Double insulation
WARNING
CAUTION
MAX
600V
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) 600 VAC or VDC.
This meter meets the IEC 61010-1 (2010) 3rd edition standard for OVERVOLTAGE CATEGORY III.
Cat III meters are protected against overvoltage transients in fixed installation at the distribution
level. Examples include switches in the fixed installation and some equipment for industrial use with
permanent connection to the fixed installation.
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:
V DC or V AC 600V DC/AC, 200Vrms on 200mV range
Function Maximum Input
mA DC 200mA 600V fast acting fuse
A DC 10A 600V fast acting fuse (30 seconds max every 15 minutes)
Ohms, Continuity 250Vrms for 15sec max
2.USE EXTREME CAUTION when working with high voltages.
3.DO NOT measure voltage if the voltage on the "COM" input jack exceeds 600V 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.
6.ALWAYS turn off the power and disconnect the test leads before opening the covers to replace
the fuse or battery.
7.NEVER operate the meter unless the back cover and the battery cover is in place and fastened
securely.
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 1 appears in the display during a measurement, the value exceeds the range you have selected.
Change to a higher range.
NOTE: On some low AC and DC voltage ranges, with the test leads not connected to a device, the
display may show a random, changing reading. This is normal and is caused by the high-input
sensitivity. The reading will stabilize and give a proper measurement when connected to a circuit.
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 highest V DC ( ) 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. Reset the function switch to successively
lower V DC positions to obtain a higher resolution reading. If the polarity is
reversed, the display will show (-) minus before the value.
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 highest V AC ( ) 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 display. Reset the function switch to successively
lower V AC positions to obtain a higher resolution reading.
DC CURRENT MEASUREMENTS
CAUTION: Do not make current measurements on the 10A scale 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 200µA DC, set the function switch to the
200µA DC () position and insert the red test lead banana plug into the
uA/mA jack.
3. For current measurements up to 200mA DC, set the function switch to the
200mA DC position and insert the red test lead banana plug into the
uA/(mA jack.
4. For current measurements up to 10A DC, set the function switch to the
10A DC range and insert the red test lead banana plug into the 10A jack.
5. Remove power from the circuit under test, then open up the circuit at the
point where you wish to measure current.
6. 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.
WARNING: To avoid electric shock, never measure continuity on circuits or wires that have voltage
on them.
1. Set the function switch to the 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. Touch the test probe tips to the circuit or wire you wish to check.
4. If the resistance is less than approximately 150 , the audible signal will
sound. If the circuit is open, the display will indicate 1 .
DIODE TEST
1. Insert the black test lead banana plug into the negative COM jack and the
red test lead banana plug into the positive diode jack.
2. Turn the rotary switch to the position.
3. Touch the test probes to the diode under test. Forward bias will typically
indicate 400 to 1000. Reverse bias will indicate 1 . Shorted devices will
indicate near 0 and the continuity beeper will sound. An open device will
indicate 1 in both polarities.
TEMPERATURE MEASUREMENTS
1. Set the function switch to the TEMP position.
2. Insert the Temperature Probe into the Temperature Socket, making sure to
observe the correct polarity.
3. Press the ºC or ºF button for the desired units.
4. Touch the Temperature Probe head to the part whose temperature you
wish to measure. Keep the probe touching the part under test 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.
Press and hold the button to turn on the display backlight function. The backlight will automatically turn off after
15 seconds.
BATTERY CHECK
The CHECK function tests the condition of the 9V battery. Set the function switch to the 200VDC range and
press the CHECK button. If the reading is less than 8.5, battery replacement is recommended.
HOLD
The hold function freezes the reading in the display. Press the HOLD key momentarily to activate or to exit the
hold function.
AUTO POWER OFF
The auto off feature will turn the meter off after 15 minutes.
LOW BATTERY INDICATION
If the icon appears in the display, the battery voltage is low and the battery should be replaced.
WRONG CONNECTION INDICATION
The icon will appear in the upper right conner of the display and the buzzer will sound whenever the positive
test lead is inserted into the 10A or uA/mA input jack and a non-current (green) function is selected. If this occurs,
turn the meter off and reinsert the test lead into the proper input jack for the function selected.
Specifications
Function Range Resolution Accuracy
DC Voltage
(V DC)
AC Voltage
(V AC)
DC Current
(A DC)
AC Current
(A AC)
Resistance
Temperature -20 to 750ºC 1ºC
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.
NOTE: Accuracy is stated at 18oC to 28oC (65oF to 83oF) and less than 75% RH.
WARNING: To avoid electrical shock, disconnect the meter from any circuit, remove the test leads
from the input terminals, and turn OFF the meter before opening the case. Do not operate the meter
with an open case.
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 Replacement
1. Remove the Phillips head screw that secures the rear battery door
2. Open the battery compartment
3. Replace the 9V battery
4. Secure the battery compartment
Never dispose of used batteries or rechargeable batteries in household waste.
As consumers, users are legally required to take used batteries to appropriate
collection sites, the retail store where the batteries were purchased, or wherever
batteries are sold.
Disposal: Do not dispose of this instrument in household waste. The user is obligated to take end-oflife devices to a designated collection point for the disposal of electrical and electronic equipment.
Other Battery Safety Reminders
o Never dispose of batteries in a fire. Batteries may explode or leak.
o Never mix battery types. Always install new batteries of the same type.
WARNING: To avoid electric shock, do not operate the meter until the battery cover is in place and
fastened securely.
NOTE: If the meter does not work properly, check the status of the fuses and batteries and ensuring