Abstract: Measurement probe (1) is used for measuring thin layers (19) on base material (20) using a magnetic or eddy current process. On probe housing (5) above a stop for guide means (3) with measurement sensor (12) and measurement pole (13) sliding element (2) for measurement sensor (12) is guided to move in the longitudinal axis of probe housing (5) as limited by a stop. Between sliding element (2) and stop (9) on guide means (3) there is first helical spring (4) by which sliding element (2) is elastically supported relative to measurement sensor (12). Between stop (9) on guide tube (3) and lower abutment (30) on probe housing (5) is second helical spring (10) which interacts with first helical spring (4) and elastically supports measurement sensor (12) in the rest state at a distance above opening (5a) for measurement pole (13) in probe housing (5).

Abstract: In the rolling probe, the measuring pole is designed as a rotating, rotationally symmetrical roller (4), such as a disk, cylinder or sphere, which directly contacts the surface of object to be measured (5) and is placed in the range of a sensor system. As a result, the maximum possible signal deviation can be fully used for the measuring. An increased measured value resolution and measuring accuracy especially in the measuring of thin sheets is achieved. Further, the actual thickness measuring takes place at the contact point with the layer to be measured. Thus, a true "one-point measuring" is involved.

Abstract: A probe for the continuous measurement of the thickness of strips of electrically conducting, magnetic or nonmagnetic strips of material, comprises a the measuring pole (7) arranged in a roller (4) with a narrow running surface. The roller (4) has a ring-shaped crowned middle part (9) in alignment with the measuring pole (7) and is pivoted on a fixed axis of rotation (10) on both sides of the measuring pole (7). The axis of rotation (10) forms part of a housing (12) which screens the measuring pole (7) against external magnetic fields. The roller (4) can consist of a suitable nonmagnetic material, such as nonmagnetic steel, bronze, titanium, ceramic, etc., and the probe can operate according to the magnetic inductive process, according to the eddy current process or according to a combination of these two processes.

Abstract: A layer-thickness meter for measuring the thickness of a non-magnetic layer upon a ferromagnetic substrate wherein the force required to raise from the layer to be measured a permanent magnet carried in a balanced lever arm is measured by means of a spring and taken as a measure of the layer thickness, the spring being stressed by rotation of a scale disc graduated in terms of layer thickness and co-operating with an index mark upon a housing of the meter, the circumferential edge of said disc being serrated or indented for engagement by a pawl so as to lock the disc in response to detachment of the permanent magnet from the layer surface, said pawl comprising a pivotally mounted bearing plate from which project two rigid stops which between them loosely embrace said lever arm at a location along said arm such that the pawl is actuated through one said stop to disengage from the disc edge when said permanent magnet is in contact with said layer surface and actuated through the other said stop to engage and lo

Abstract: The calibration of magnetic gauges used for measuring the thickness of a layer applied to a base can be accomplished by the use of a test sheet composed of an essentially uncoated material which exerts a lesser influence on the gauge for a given thickness than the material comprising the base upon which the measured layer is applied. An uncoated test sheet of a certain thickness, when brought into contact with the pole piece of a thickness gauge, will produce a reading equivalent to that produced when the gauge measures a layer of predetermined thickness applied to the usual base material. For calibrating a gauge used to measure the thickness of a non-magnetic layer on a ferromagnetic base, the test sheet may be a material of less magnetic conductivity, permeability and/or saturation than that of the usual base material. A non-limitative example of a material suitable for use as a test sheet is pure nickel.

Abstract: A probe for electromagnetic measurement of the thickness of a layer of material applied to a base of dissimilar material consists of an elongated ferro-magnetic core surrounded by an electrical coil several diameters larger than the diameter of the core and having one end placed close to the plane of the pole face of the core so that measurements involving magnetic materials can be undertaken by utilizing variations in magnetic flux path at low energization frequencies while measurements involving electrically conductive materials are undertaken by utilizing eddy currents induced at high energization frequencies.