Extech 480826 Operating Manual

User Guide

Three Axis Electromagnetic Field (EMF) Meter

Model 480826

Introduction

Congratulations on your purchase of Extech’s Model 480826 Electromagnetic Field
(EMF) Meter. The Model 480826 is a battery powered meter that measures and displays
EMF in Gauss and Tesla units with a frequency bandwidth of 30 to 300Hz. The 3 axis
sensor allows for three component (xyz) measurement coverage. The Model 480826 is
specifically designed to determine the magnitude of electromagnetic fields generated by
power lines, computers electric appliances, televisions and many other similar devices.
This meter is shipped fully tested and calibrated and, with proper use, will provide years
of reliable service.

Meter Operation

1. Press the POWER button to turn the meter ON.

2. Press the UNIT button to select either µTesla or mGauss units.

3. If the approximate range of the measurement is known, select the suitable meter range
using the RANGE button. For unknown measurements, start with the highest range
and work down through the ranges until the optimum range is reached.

4. Hold the probe by its handle and move it slowly toward the object under test. If the LCD
display is completely blank or if the low battery symbol appears on the LCD, check the
9V battery.

5. Notice that the field intensity reading increases as you move closer to a field.

6. Use the XYZ button to read the EMF measurement in the X, Y, or Z axis.

7. If the meter’s display indicates a “1” on the left side of the LCD, an overload condition
exists. This indicates that the measured radiation is higher than the capability of the
currently selected range. Find the appropriate range using the RANGE button as
described above.

Measurement Notes

Due to environmental electromagnetic interference the display may show small EMF
values before testing. This is normal and due to the high sensitivity of the meter. Once a
signal is detected by the sensor, the meter will display accurately.

If the object under test is turned off in the middle of testing, the meter reading should fall
close to zero unless a field from another source is detected.

Data Hold feature

To freeze a displayed reading, press the HOLD button. The DH display icon will switch
on. To unlock the display and return to normal operation, press the HOLD button again.
The DH indicator will switch off.

Battery Replacement

When the low battery icon appears on the left corner of the LCD, the 9V battery has fallen
to a critically low voltage level and should be replaced as soon as possible. The battery
compartment cover is located at the bottom rear of the meter. Remove the Phillips head
screw that secures the battery compartment and slide off the battery compartment cover.
Replace the battery and secure the compartment cover before use.

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480826 V3.0 3/06