Extech Instruments MA140 User Manual page 2

Introduction
Thank you for selecting the Extech MA140 300A AC True RMS Mini Clamp Meter with Non‐Contact
Voltage Detector. The MA140 is small in size but rugged in performance.
The MA140 measures AC current to 300A and offers a Smart Data Hold feature, display Backlight,
In‐rush Current mode, Low Pass Filtering (LPF), and a non‐contact Volt‐Detection feature that
senses electrical sources safely.
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, Product Registration, and Customer Support.
Safety Information – Please Read First
To ensure the safe operation and service of the meter, follow these instructions closely. Failure to
observe warnings can result in severe injury.
WARNINGS
WARNINGS identify hazardous conditions and actions that could cause BODILY HARM or DEATH.

Individual protective equipment should be used if HAZARDOUS LIVE parts in the installation where
measurements are to be carried out could be accessible.

If the equipment is used in a manner not specified by the manufacturer, the protection provided by the
equipment may be impaired.

To reduce the risk of fire or electric shock, do not expose this product to rain or moisture.

Verify the meter operation by measuring a known voltage. If in doubt, have the meter serviced.

Do not apply more than the rated voltage as marked on the meter.

To avoid false readings that can lead to electric shock and injury, replace battery as soon as the low
battery indicator appears.

Do not use the meter in or around explosive gas or vapor.

Please keep fingers and hands behind the finger guards.

Do not expose meter to extremes in temperature or high humidity.

De‐energize the installation under test or wear suitable protective clothing when placing or removing
the current clamp from a test setup.

Do not apply/remove the current clamp to/from UNINSULATED HAZARDOUS LIVE conductors which may
cause electric shock, electric burn, or arc flash.
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