Iwatsu SS-281A-H Instruction Manual page 27

4.3.2 To Minimize Influence of Fluctuations in Voltage
If there is a part whose voltage fluctuates around the Rogowski Coil Sensor,
electrostatic coupling between the part and the Rogowski Coil will occur.
This may influence the output from this instrument.
If possible, place the Rogowski Coil Sensor away from the part whose
voltage fluctuates. This will improve noise caused by electrostatic coupling.
For instance, it is improved to measure the electric current that flows to IGBT
in the emitter terminal connected with not the collector terminal that changes
greatly the voltage but a constant voltage and is improved the capacitive
coupling noise.
4.3.3 Use caution to heat generated by induction heating
In a strong magnetic field due to high frequency and large current, the metal
may generate heat due to induction heating. (Applicating: this is IH's
electromagnetic cooker)
Since the Rogowski coil has a coiled structure in which a copper wire is
wound around a core material, the coil itself, which is a metal, may generate
heat by the same principle.
The Rogowski coil can not be used even within the absolute maximum di/dt
under conditions such that the coil itself generates heat due to induction
heating.
CAUTION
<Example in which there is a possibility of heat generation by induction
heating>
· Drive current of electromagnetic cooker etc.
· Driving current of welding machines, quenching devices, etc. using
induction heating
· High frequency power supply output used for semiconductor manufacturing
equipment, high frequency drive current
・ Do not use under conditions where the sensor
coil generates heat due to induction heating.
Even if the absolute maximum di/dt is within the range, the
coil itself is metal, so induction heating causes the coil itself
to generate heat, which may cause smoke, fire, or
malfunction.
Chapter 4 Measurement
23