English User's Manual

User Guide
Three Axis Electromagnetic Field (EMF) Meter
Model 480826
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.
Meter Description
Sensor plug shown inserted in meter’s sensor jack
LCD Display
XYZ axis select button
Manual Range button
Power button
Data Hold button
Unit select button
Sensor grip handle
10. Tripod mount
11. Pull-out tilt stand
12. Battery compartment access screw
13. Battery compartment cover
3-1/2 digit (2000 count) LCD
Measurement rate
Approx. 0.4 seconds
Ranges and resolution
20µTesla (0.01) and 200mGauss (0.1)
200µTesla (0.1) and 2000mGauss (1)
2000µTesla (1) and 20,000mGauss (10)
NOTE: 1 µTesla = 10 mGauss
± (4%FS + 3 digits) for 20µTesla and 200mGauss ranges
(stated for 50/60Hz)
± (5%FS + 3 digits) for 200µTesla and 2000mGauss
± (10%FS + 5 digits) 2000µTesla & 20,000mGauss ranges
Frequency bandwidth
30 to 300Hz
Over-range indication
“1___” is displayed
Temperature: 0 to 50°C (32 to 122 F)
RH: 90% max. from 0 to 35°C (32 to 95°F);
80% max. from 35 to 50°C (95 to 122°F)
Power source
9V Battery
Power consumption
Approx. 2.7mA DC
Meter: 195 x 68 x 30mm (7.6 x 2.6 x 1.2”)
Probe: 70 x 58 x 220mm (2.8 x 2.3 x 8.7”)
Sensor Cable Length
1m (3 ft) approx.
460g (16.2 oz.) including probe and battery
EMF Exposure
The effect of EMF exposure is a modern day concern. At the time of this writing, to the best of our
knowledge, no standards or recommendations exist regarding limits of EMF exposure. Exposure
limits of 1 to 3mG have been suggested by several international bodies. Until evidence suggests
that there is not a health risk associated with EMF exposure, common sense would dictate that a
practice of minimal exposure be exercised.
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.
You, as the end user, are legally bound (Battery ordinance) to return all used batteries
and accumulators; disposal in the household garbage is prohibited!
You can hand over your used batteries / accumulators at collection points in your
community or wherever batteries / accumulators are sold!
Disposal: Follow the valid legal stipulations in respect of the disposal of the device at the
end of its lifecycle
Copyright © 2011 Extech Instruments Corporation (a FLIR company)
All rights reserved including the right of reproduction in whole or in part in any form.