Extech Instruments MA440 User Manual page 2

Introduction
Thank you for selecting the Extech EX44x Series 400A Clamp Meter.
The MA440 is a 400A AC Clamp meter with a total of 9 functions.
The MA443 is a 400A True RMS AC Clamp meter that offers 10 functions including TRMS AC
measurements and Type K Thermocouple
The MA445 is a 400A AC/DC True RMS Clamp meter with 11 functions including DC Current, TRMS
AC measurements, and Type K Thermocouple.
The MA44x series are hand‐held, 4000 count clamp meters. This meter series measures AC/DC
voltage, AC current, DC current (MA445), resistance, diode, continuity, capacitance, temperature
(MA443 and MA445), frequency, and duty cycle. In addition, these meters offer Display hold, MIN‐
MAX (MA443 and MA445), Relative mode, NCV (non‐contact voltage detection), and automatic
power OFF.
In addition to the meter, the packaging includes Instructional documentation (Quick Start), Test
Leads, K‐type temperature probe (MA443 and MA445), batteries, and a pouch.
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
To ensure the safe operation and service of the meter, follow these instructions closely. Failure to observe
warnings can result in severe personal injury or death.
These instruments are designed and produced in strict accordance with IEC/EN61010‐1, IEC/EN 61010‐2‐032,
and IEC/EN 61010‐2‐033, safety standards, and comply with the safety standard for double insulation,
overvoltage CAT III 600V and pollution level 2. Please observe all operational and safety instructions
otherwise the protection provided by instrument may be compromised.
These instruments conform to UL standard 61010‐1, 61010‐2‐032, 61010‐2‐033; these instruments are
certified to CSA standard C22.2 no. 61010‐1, IEC standard 61010‐2‐032, and IEC standard 61010‐2‐033.
CAT III: Applicable to test and measuring circuits connected to the distribution section of a building's low
voltage mains installation; before use of these instruments please observe and obey all safety instructions.
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