Saluki SER Series User Manual page 35

EMI Receiver Instructions for Use
Electric field strength E(dBBμv/m)=V(dBBμv )+AF(dB/m)
Magnetic field strength H(dBBμA/m)=
Magnetic induction (magnetic flux
In the formula: V(dBBμv ) —— measured
AF(dB/m)——electric field probe correction factor
AF(dBs/m)——Correction coefficient of magnetic field probe
Measuring with a diagnostic probe is different from the method of measuring according to the military standard. The diagnostic measurement is a near-field measurement, and the near-field measurement is a
With a probe, the probe is in close proximity to the radiation source. The measurement according to the electromagnetic compatibility standard basically belongs to the far-field measurement, and the far-field measurement
The amount is with an antenna. The military standard requires that the distance between the antenna and the device under test is 1m. In order to eliminate the environmental electromagnetic interference, the radiation emission
Radiation measurements must be carried out in a shielded dark room.
Probe Measurement Error Analysis: There are many factors affecting near-field measurement
(1) The magnetic component of the signal is coupled to the probe through magnetic induction, while the electrical component is coupled through capacitive
onto the probe. Since the distributed capacitance is not fixed, the induced electric component also changes, so each measurement
The repeatability is poor. (2) Influence of the probe: when the probe is placed near the radiation source, due to the presence of the probe, the
The capacitance of the source is increased, thereby changing the distribution of the current at the interaction point, thus changing the flux density of the source
Spend. This can also lead to measurement errors. (3) The wave impedance in the near field changes and is particularly sensitive to the position of the probe.
(4) The influence of the human body: when a person holds the probe, the electrical signal component can pass through the separation between the human body and the probe.
The distributed capacitance is coupled to the probe, and the position of the person or the method of holding the probe is different, the distributed capacitance is also different.
same.
During diagnostic measurement, keep the human body as far away from the probe and measurement cable as possible to eliminate the influence of the human body. Due to electromagnetic waves
There is a problem with the direction of polarization, so the direction of the probe should be rotated during the measurement in order to measure the largest signal. For phase
For measurement, the conditions before and after the measurement should be as similar as possible. As long as you pay attention to the measurement method, you can reduce the measurement error.
V(dBBμv )+AF(dBs/m)
density) B(dBpT) = H(dBÿA/m)+2dB=
value of spectrum analyzer
V(dBBμv )+AF(dBs/m) +2dB
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