US 11,946,740 B2
Coating thickness measurement instrument
Philip Anthony May, Lancashire (GB); Simon Trevena Coulton, Yorkshire (GB); Alan James Dodd, Bolton (GB); and Maria Isabel Jimenez-Lopez, Derby (GB)
Assigned to Elcometer Limited, Manchester (GB)
Filed by Elcometer Limited, Manchester (GB)
Filed on Nov. 17, 2021, as Appl. No. 17/528,792.
Claims priority of application No. 2018269 (GB), filed on Nov. 20, 2020.
Prior Publication US 2022/0163315 A1, May 26, 2022
Int. Cl. G01B 7/06 (2006.01)
CPC G01B 7/105 (2013.01) 17 Claims
OG exemplary drawing
 
1. A coating thickness measuring instrument comprising:
a magnetic induction probe comprising at least one drive coil and at least one pick-up coil;
a driver for driving an alternating drive current in the or each drive coil and comprising a first modulator configured to scale the drive current in the or each drive coil according to a first scaling factor;
a detector for detecting an output of the or each pick-up coil;
a second modulator configured to scale an output of the detector according to a second scaling factor; and
a processor configured to: apply a transfer function to an output of the second modulator to produce an instrument output corresponding to a measured coating thickness; and change both the first and second scaling factors simultaneously based on the instrument output.