Electromagnetic conductivity measurement system with improved drift correction

摘要

The method involves applying a medium (3) by a transmitting coil having an alternating magnetic field, i.e. a primary field, so that currents are induced in the medium to form another magnetic field, i.e. secondary field. The secondary field is measured with a receiver coil to evaluate the conductivity of the medium. The primary field at the location of the transmitter coil is measured directly or indirectly, so that the primary field is evaluated to the field at the location the receiver coil.