USER MANUAL
Mini Multimeter
with Non-Contact Voltage Detector (NCV)
Model EX310
Introduction
Congratulations on your purchase of the Extech EX310 MultiMeter. The EX310 offers AC/DC Voltage,
AC/DC Current, Resistance, Diode, and Continuity testing plus a built-in non-contact Voltage Detector.
Proper use and care of this meter will provide many years of reliable service. For copies of this user
manual in other languages please visit the
www.extech.com
website.
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
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 600V.
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.
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
V DC or V AC
mA AC/DC
A AC/DC
Resistance, Diode Test, Continuity
2.
3.
4.
5.
6.
7.
8.
Maximum Input
600V AC and DC
200mA DC/AC
10A DC/AC (for 30 seconds max. every 15 mins.)
250V DC/AC
USE EXTREME CAUTION
when working with high voltages.
DO NOT
measure voltage if the voltage on the "COM" input jack exceeds 600V above earth
ground.
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.
ALWAYS
discharge filter capacitors in power supplies and disconnect the power when making
resistance or diode tests.
ALWAYS
turn off power and disconnect test leads before opening the covers to replace the fuse
or battery.
NEVER
operate the meter unless the back cover and the battery and fuse covers are in place
and fastened securely.
If the equipment is used in a manner not specified by the manufacturer, the protection provided
by the equipment may be impaired.
2
EX310A-en-GB_v7.7 10/17
CAUTIONS
Improper use of this meter can cause damage, shock, injury or death. Read and understand
this user manual before operating the meter.
Always remove the test leads before replacing the battery or fuses.
Inspect the condition of the test leads and the meter itself for any damage before operating the
meter. Repair or replace any damage before use.
Use great care when making measurements if the voltages are greater than 25VAC rms or
35VDC. These voltages are considered a shock hazard.
Warning! This is a class A equipment. This equipment can cause interference to devices in the
home; in this case the operator can be required to carry out adequate measures to prevent
interference.
Always discharge capacitors and remove power from the device under test before performing
Diode, Resistance or Continuity tests.
Voltage checks on electrical outlets can be difficult and misleading because of the uncertainty
of connection to the recessed electrical contacts. Other means should be used to ensure that
the terminals are not "live".
If the equipment is used in a manner not specified by the manufacturer, the protection provided
by the equipment may be impaired.
This device is not a toy and must not reach children’s hands. It contains hazardous objects as
well as small parts that children could swallow. In case a child swallows any of the parts,
please contact a physician immediately.
Do not leave batteries and packing material unattended; they can be dangerous for children.
In case the device is going to be unused for an extended period of time, remove the batteries
to prevent them from draining.
Expired or damaged batteries can cause cauterization on contact with skin. Always use
suitable hand protection.
See that the batteries are not short-circuited. Do not throw batteries into fire.
3
EX310A-en-GB_v7.7 10/17
Description
1. AC Voltage Detector Sensor
2. AC Voltage Detector indicator light
3. Display (LCD)
4. Non-contact AC Voltage Detector test button
5. Rotary function dial
6. 10 ampere test lead jack
7. COM test lead jack
8. Test lead jack for voltage, milliamp,
resistance/continuity, and diode functions
9. Protective rubber holster (must be removed to
access the rear battery compartment)
Symbols
•)))
Continuity
Diode
Battery status
AC
DC
m
k
V
A
Ω
AC
DC
milli (10
-3
) (volts, amps)
kilo (10
3
) (ohms)
Volts
Amps
Ohms
Alternating current
Direct current
4
EX310A-en-GB_v7.7 10/17
Operating Instructions
WARNING:
Risk of electrocution. High-voltage circuits, both AC and DC, are very dangerous and
should be measured with great care.
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.
NON-CONTACT AC VOLTAGE DETECTOR (NCV)
The EX310 can detect the presence of AC voltage (from 100 to 600VAC) simply by being held very
near to a voltage source.
WARNING:
Test the AC voltage detector on a known live circuit before each use.
WARNING:
Before using the meter in the AC Voltage Detector mode, verify that the battery is fresh
by confirming characters appear on the LCD when the function dial is turned to any position. Do not
attempt to use the meter as an AC Voltage Detector if the battery is weak or bad.
The NCV function works on any rotary switch position.
1.
2.
Test the detector on a known live circuit before use.
Press and hold the NCV button for the duration of the test. The meter will
beep once when the button is pushed and the battery icon will appear briefly
before the display goes blank.
Hold the top of the meter very close to the voltage source as shown.
If voltage is present, the rim of the LCD display will flash a bright orange and
an audible warning will sound.
3.
4.
5
EX310A-en-GB_v7.7 10/17
