Elma 593R
9
4.3 Use E-field sensor
The actual 3-channel sensor is located in the head part 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 for frequencies is from
10MHz to 8GHz
.
The meter is a small portable instrument that measures the electric field presented in the
atmosphere of the measurement sensor surroundings.
The measurement of the field is done by moving the aerial of the sensor in the desired measured
environment.
You obtain a direct wide band measurement 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 handing. Its sensitive part 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 (
A/m, mA/m) and power density
units (
W/m
2
, mW/m
2
, W/m
2
,
W/cm
2
or mW/cm
2
) 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 instantaneous or result according to one of three
modes which can be selected:
•
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.
•
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
