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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 (
µ
A/m, mA/m) and
power density units (
µ
W/m
2
, mW/m
2
, W/m
2
,
µ
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 four modes
which can be selected :
•
Instantaneous
: The display shows the last value measured by the
sensor, no symbol is displayed.
