Extech Instruments 480836 User manual

User's Guide
RF EMF Strength Meter
Model 480836

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1.0 - Safety Information
CAUTION
•Before making a measurement, check if the low battery symbol ( +) is
shown on the display when the meter is switched on. Replace the
battery if the symbol is displayed.
•In the case of prolonged storage, it is preferable to remove the battery from
the meter.
•Avoid shaking the meter, particularly in the measurement mode.
•The accuracy and function of the meter may be adversely affected by
exceeding the specified limits as well as by improper handling.
DANGER!
•Use caution when working in the vicinity of powerful radiation sources.
•Persons with electronic implants (e.g. cardiac pacemakers) should avoid
powerful radiation sources.
•Observe the local safety regulations.
•Observe the operating instructions for equipment that is used to generate or
conduct electromagnetic energy.
•Be aware that secondary radiators (e.g. reflective objects such as a metallic
fence) can cause a local amplification of the field.
•Be aware that the field strength in the near vicinity of radiators increases
proportionally to the inverse cube of the distance. This means that enormous
field strengths can result in the immediate vicinity of small radiation sources
(e.g. leak in waveguides, inductive ovens).
•Field strength measuring devices can underrate pulsed signals, particularly with
radar signals in which case significant measurement errors can arise.
•All field strength measuring devices have a limited specified frequency range.
Fields with spectral components outside of this frequency range are generally
incorrectly evaluated and tend to be underrated. Before using field strength
measuring devices, you should thus be certain that all field components to be
measured lie in the specified frequency range of the measuring device.

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2.0 - Introduction
2-1 Fundamentals
Electromagnetic Radiation
This meter is used to indicate radiated electromagnetic fields. Wherever there is
a voltage or a current, electric (E) and magnetic (H) fields arise. Examples
include the electromagnetic fields from radio broadcasting and TV transmitters.
Electric Field Strength
This is a field vector quantity that represents the force (F) on an infinitesimal unit
positive test charge (q) at a point divided by that charge. Electric field strength is
expressed in units of volts per meter (V/m).
Use the units of electric field strength for measurements in the following situations:
•In the near-field area of the source
•Where the nature of the electromagnetic field is unknown
Magnetic field strength (H) :
This is a field vector that is equal to the magnetic flux density divided by the
permeability of the medium. Magnetic field strength is expressed in units of
amperes per meter (A/m).
Power density (S) :
Power per unit area in the direction of propagation, usually expressed in units of
watts per square meter (W/m2) or, for convenience, units such as milliwatts per
square centimeter (mW/cm2).
The characteristic of electromagnetic fields :
Electromagnetic fields propagate as waves and travel at the speed of light (c).
The wavelength is proportional to the frequency.
λ(wavelength) = c (speed of light)
f (frequency)
Near-field is assumed if the distance to the field source is less than three
wavelengths. For far-fields, the distance is more than three wavelengths. In the
near-field, the ratio of electric field strength (E) and magnetic field strength (H) is
not constant, so measure each separately. In the far-field, however, it is enough
to just measure one field quantity, and compute the other accordingly.
2-2 Application
High frequency (RF) electromagnetic wave field strength measurement
Mobile phone base station antenna radiation power density measurement
Wireless communication applications (CW, TDMA, GSM, DECT)
RF power measurement for transmitters
Wireless LAN (Wi-Fi) detection, installation
Spy camera, wireless bug finder
Cellular/Cordless phone radiation safety level
Microwave oven leakage detection
Personal, environmental EMF safety

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2-3 Features
This meter is a broadband device for monitoring high-frequency radiation in the specific
ranges of 900MHz, 1800MHz, and 2.7GHz. Other measurements can be made, for
reference purposes only, using the entire range of 50MHz to 3.5GHz. The non-
directional electric field and high sensitivity also allow measurements of electric field
strength in TEM cells and absorber rooms.
The unit of measurement and the measurement types are expressed in units of electrical
and magnetic field strength and power density.
At high frequencies, the power density is of particular significance. It provides a measure
of the power absorbed by a person exposed to the field. This power level must be kept
as low as possible at high frequencies. The meter can be set to display the
instantaneous value, the maximum value measured or the average value. Instantaneous
and maximum value measurements are useful for orientation, e.g. when first entering an
exposed area.
Measurements in the specific frequency ranges of 900MHz, 1800MHz, and 2.7GHz
For isotropic measurements of electromagnetic fields
Non-directional (isotropic) measurement with three-channel measurement sensor
High dynamic range due to three-channel digital processing
Configurable alarm threshold and memory function

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3.0 - Specifications
3-1 General Specifications
•Measurement method: Digital, triaxial measurement.
•Directional characteristic: Isotropic, triaxial.
•Measurement ranges: One continuous range
•Display resolution: 0.1mV/m, 0.1μA/m, 0.1μW/m2, 0.001μW/cm2
•Setting time: Typically 1s (0 to 90% of measurement value).
•Display refresh rate: Typically 0.5 seconds
•Display type: 4-digit Liquid-crystal display (LCD)
•Audible alarm: Buzzer.
•Units: mV/m, V/m, μA/m, mA/m, μW/m2, mW/m2, W/m2, μW/cm2, mW/cm2
•Display value: Instantaneous measured value, maximum value, or maximum
average value.
•Alarm function: Adjustable threshold with ON/OFF.
•Manual data memory and read storage: 99 data sets.
•Dry batteries: 9V NEDA 1604/1604A
•Battery life: > 15 hours
•Auto power off: 15 minutes.
•Operating temperature range: 0°C to +50°C
•Operating humidity range: 25% to 75%RH
•Storage temperature range: -10°C to +60°C
•Storage humidity range: 0% to 80%RH
•Dimensions: Approx. 60(W)×60(T)×237(L)mm.
•Weight (including battery): Approx. 200g
•Accessories: Instruction manual, battery, carrying case.

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3-2 Electrical Specifications
Unless otherwise stated, the following specifications hold under the following
conditions:
•The meter is located in the far-field of a source, the sensor head is pointed towards
the source.
•Ambient temperature: +23℃±3℃
•Relative air humidity: 25% to 75%
Sensor type: Electrical field (E)
Frequency ranges: 900MHz, 1800MHz, and 2.7GHz (measurements can be made, for
reference purposes only, using the entire range of 50MHz to 3.5GHz)
Specified measurement range:
•CW signal (f > 900MHz): 20mV/m to 108.0V/m ,
53μA/m to 286.4mA/m,
1μW/m2 to 30.93W/m2,
0μW/cm2 to 3.093mW/cm2
Dynamic range: Typically 75dB
Absolute error at 1 V/m and 50 MHz: ±1.0dB
Frequency response:
•Sensor (taking into account typical CAL factors):
±1.0dB (900MHz, 1800MHz)
±2.4dB (2.7GHz)
•Isotropy deviation: Typically ±1.0dB (f>900MHz)
•Overload limit: 10.61mW/cm2(200V/m)
•Thermal response (0 to 50℃): ±0.2dB

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4.0 - Operation
4-1 Front Panel Description
(1). E-field sensor.
(2). LCD display.
(3). MAX/AVG/↵key :
cPress this key to scroll through the following:
“Instantaneous”→“Max. instantaneous” →
“Average” →“Max. average”.
dIn the read mode, press this key to exit.
eIn the alarm setting mode, press this key to store the
setting value.
fPress and hold this key while turning the meter on to
disable the audible sound. The “ ” symbol will
disappear.
(4). MODE/ALARM key :
cPress this key to change the sensor axis: “XYZ axis”
→“X axis” →“Y axis” →“Z axis”.
dPress and hold this key while turning the meter on to
switch the device to the alarm setting mode.
ePress this key for 2 seconds to switch the alarm
function on or off.
(5). UNIT/ key:
cPress this key to change the units: “mV/m or V/m” →
“μA/m or mA/m” →“μW/m2 or mW/m2 or W/m2“ →“μW/cm2 or mW/cm2“
dPress this key for 2 seconds to turn the backlight on. The backlight turns off
automatically in 15 seconds later.
ePress and hold this key and turn on the meter again to disable the backlight auto off
function.
(6). key: Press this key to turn the meter on or off.
(7). MEM/▲key:
cPress this key momentarily to store one data set to memory.
dPress and hold this key while turning the meter ON to enter the manual clear
recorded data mode.
eIn the manual data reading mode, press this key to read the next stored data.
fIn the alarm setting mode, press this key to increase the setting value.
(8). READ/▼key:
cPress this key to switch to the manual data reading mode.
dPress and hold this key while turning the meter on to disable the auto power off
function.
eIn the manual data reading mode, press this key to read the previous stored data.
fIn the alarm setting mode, press this key to decrease the setting value.

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4-2 LCD display description
(1). : Auto power off function on / off.
(2). : Audible sound function on / off.
(3). MAX: Maximum measured value displayed.
MAX AVG: Maximum average value displayed.
(4). AVG: Average measured value displayed.
(5). +: Low battery indication.
(6). Units : mV/m and V/m : Electric field strength.
μA/m and mA/m : Magnetic field strength.
μW/m2, mW/m2, W/m2, μW/cm2and mW/cm2: Power density
(7). : Measured value displayed as per selected mode and selected units.
(8). : Manual data memory mode indication.
(9). : Manual data memory address number (1~99).
: The manual data memory clear mode.
(10). : Stored measured value to memory indication.
(11). ALM: Alarm function on / off or alarm setting indication.
(12). ▲: Displays when the alarm function is on and the instantaneous measured value
exceeds the limit value indication.
(13). : Analog bargraph of each axis (X,Y or Z) measured dynamic range indication
for observing trends.
(14). X: X axis measured value displayed.
(15). Y: Y axis measured value displayed.
(16). Z: Z axis measured value displayed.

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4-3 Using E-field sensor
The 3-channel sensor is located at the top of the meter. The three voltages generated
by the sensor are fed back to the meter. In far-fields, an E-field sensor is preferable due
to the greater bandwidth. The E-field sensor frequency ranges from 50MHz to 3.5GHz
(calibration accuracy only supports measurements in the 900MHz, 1800MHz, and
2.7GHz ranges, other measurements made in the 50MHz to 3.5GHz range are for
reference purposes only).
The meter is a small portable instrument that measures the electric field in the atmosphere of
the sensor’s surroundings. The measurement of the field is done by moving the aerial of the
sensor in the desired measured environment.
A direct wide band measurement is obtained of the field that the measurement sensor is
subjected to. To find the value of the field emitted by a source of interference, simply
point the aerial towards it and get as close as possible (the value of the field is inversely
proportional to the distance of the sensor/emission source). The operator must take care
not to be between the source of disturbance and the zone to be checked. The human
body shields electromagnetic fields. The E-field sensor is isotropic; it does not require
special handling. It measures the field according to 3 axes without the aerial having to
be moved in the 3 planes. Simply point it at the target to make the measurement.
4-4 Explanatory notes
4-4-1 Units of measurement
The meter measures the electrical component of the field; the default units are those of
electrical field strength (mV/m, V/m). The meter converts the measurement values to the
other units of measurement, i.e. the corresponding magnetic field strength units (μA/m,
mA/m) and power density units (μW/m2, mW/m2, W/m2, μW/cm2or mW/cm2) using the
standard far-field formulate for electromagnetic radiation.
The conversion is invalid for near-field measurements, as there is no generally valid
relationship between electrical and magnetic field strength in this situation. Always
use the default units of the sensor when making near-field measurements.
4-4-2 Result modes
The bar graph display always shows each axis (X, Y or Z) the instantaneous
measured dynamic range value. The digit display shows the measurement
according to one of four selectable modes:
•Instantaneous: The display shows the last value measured by the sensor, no
symbol is displayed.
•Maximum instantaneous (MAX): The digital display shows the highest
instantaneous value measured, the “MAX” symbol is displayed.
•Average (AVG): The digital display shows the average value measured, the “AVG”
symbol is displayed.
•Maximum average (MAX AVG): The digital display shows the highest average
value measured, the “MAX AVG” symbol is displayed.
t
Max. Hold
Average Actual
Max. Average
Field strength

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4-4-3 Alarm limit value (ALM)
The alarm limit value is used to monitor the display value and control the alarm
indication function. The alarm limit value can be edited in the displayed V/m unit; the
smallest value that can be set is 0.05V/m.
NOTE: Alarm limit function can only be used for the total three axial measurement value.
4-4-4 Calibration Factor (CAL)
The calibration factor “CAL” corrects for variances in the frequency response of the
field sensor. When a known RF calibration source is not available for precise
calibration, a calibration factor of 1.00 is sufficient for most applications.
E-Field typically calibration data:
Frequency CAL
50MHz 3.16
100MHz 2.46
200MHz 2.01
300MHz 1.91
433MHz 0.55
500MHz 0.37
600MHz 2.41
700MHz 4.63
800MHz 4.21
900MHz 4.47
1GHz 2.80
1.2GHz 1.38
1.4GHz 3.26
1.6GHz 1.25
1.8GHz 1.87
2GHz 1.67
2.2GHz 1.95
2.45GHz 1.93