Patent ID: 10928178

Abstract:
The invention relates to a method for measuring the thickness of non-magnetisable layers (51) on a magnetisable base material (52), the permeability of which is not known, having a measuring probe (11), which has a probe head (17), which comprises a pot core (31) having a first and second coil (36, 37), which lie on a common geometric axis (16), and in which the first and second coils (36, 37) form a first coil pair (38), and which has a bearing calotte (21) in a common axis (16), in which the probe head (17) is placed on the layer (51) to measure the thickness of the layer (51) on the base material (52), wherein a first interaction volume is detected by the first coil pair (38) with a field focusing caused by the pot core (31), a second interaction volume is detected by a second coil par (44) with a first and second coil (42, 43), which is arranged outside the pot core (31) and jointly with the geometric axis (16) without field focusing by the pot core (21), and the detected first and second base material volume is processed in an evaluation device (13) and compared to each other for compensating a permeability of the base material (52), on which the layer (51) to be measured is applied, and a layer thickness is output for the measured layer (51), which is corrected by the influence of the permeability of the base material (52).