Use of the I-W-A
measuring system is only possible
with electrically conductive materials
on the object to be measured.
Optimal measuring results are
obtained on ferromagnetic materials.
Changes to the dielectric (air,
gas, vacuum, oil, water, emulsion,
rubber, plastic or glass etc.)
does not effect the measuring
accuracy. The homogenity of the
object to be measured is an important
prerequisite for exact measuring
results.
Along with a high-quality capacitor,
the measuring coil is interconnected
to an oscillating circuit, a freely
running oscillator supplied with
current. The magnetic field generated
by the measuring coil induces
eddy currents in the electrically
conductive material to be detected.
This corresponds to a power loss
in the coil and to increased attenuation.
With the distance of the sensor
to the object to be measured,
the alternating current resistance
of the coil changes, whereby the
oscillating current is less attenuated
with a growing object distance
and, for this reason, the amplitude
increases. The attenuation of
the measuring coil, however, is
not only dependent on the energy
losses in the magnetic field,
but also on the winding resistance
of the measuring coil and the
supply line resistances. |
Sensors
Strain
gauge - Application