Specifications

Figure 4-21. Eddy current effect and magnetic flux directivity of device
4.8.5 Variance in environmental temperature
Temperature influences the electrical properties of materials used for the test fixtures and cables.
When the test port is extended using a coaxial cable, the dielectric constant of the insulation layer
(between the inner and outer conductors) of the cable, as well as physical cable length, will vary
depending on the temperature. The effective electrical length of the cable varies with the dielectric
constants, thus resulting in measurement errors. Bending the cable will also cause its effective elec-
trical length to change. Keep the extension cable in the same position as it was when calibration was
performed.
4-25
a) Metallic object near the leakage flux
of inductor will cause an eddy current
effect. This effect increases as the
distance of the metallic object from
the inductor decreases.
b) Inductor with leakage flux directivity.
Turning the inductor by 90 degrees
reduces the eddy current as shown in
figure (c).
c) Metallic object in parallel with the
leakage flux causes less eddy current.
d) Inductor with less leakage flux
directivity. The eddy current effect is
almost independent from the direction
of inductor’s side faces.