Wall thickness monitor for electrical induction furnaces - measures and compares electrical magnitudes sensed by induction coil

摘要

The furnace crucible wall thickness monitoring system is used in an electrical induction furnace. The monitoring system senses variation of the electrical measured value at a specified time in the cycle. This electrical magnitude is evaluated by a solenoid forming part of the furnace enclosing the induction heating coil. The measured magnitude is compared with a reference value. It is monitored to aim for equality of both measured values in time. The reference magnitude found by the part of the induction solenoid and the whole solenoid are monitored according to the time variation of the ratio. The measures quantities can be for example power, voltage or resistance.