JPH0316005Y2 - - Google Patents

Description

[Detailed explanation of the invention] Background of the invention The invention relates to non-destructive testing of metals, and more specifically, measures the thickness of a magnetic flux-conducting cladding material that is pasted onto a magnetic flux-conducting base material and has a different magnetic permeability from that of the base material. related to a device for

Vessels, pipes, used in nuclear, petrochemical, and other industries requiring erosion or thermal protection;
and other parts are sometimes manufactured by applying a cladding material selected for its particular properties onto a base material. This cladding construction is more economical than manufacturing the entire vessel, pipe or other component entirely from cladding material. Clad materials are sometimes surface-finished by machining or grinding the clad material after welding it to the base material of a vessel, pipe, or other component. Although the initial cladding thickness is estimated from the particular welding method used to apply the cladding, it is difficult to estimate the thickness of the cladding after machining or polishing.

Ultrasonic methods have been used to measure the thickness of the cladding material by detecting the interface between the cladding material and the base material. The ultrasonic method detects interfaces better when the clad material is not tightly attached to the base material than when it is more closely attached to the base material. In the more favorable condition where the cladding material is more tightly bound to the base material, reliable ultrasonic determination of the cladding thickness is not desired.

Another method used is to measure the cladding thickness by pulling a magnet in a plane perpendicular to the surface of the cladding material attached to the base material. This method measures the breaking force and correlates that force to cladding thickness. This method of determining cladding thickness is limited to applications where the cladding material has low magnetic permeability and the base material has high magnetic permeability.

Therefore, there is a need for a non-destructive device for determining the thickness of a flux conducting cladding material applied to a flux conducting matrix having a magnetic permeability different from that of the cladding material.

SUMMARY OF THE INVENTION The present invention uses a core transformer to non-destructively determine the thickness of the flux-conducting cladding material. The present invention is applied to a structure in which a magnetic flux conducting cladding material is attached to a magnetic flux conducting base material, and the magnetic permeability of the cladding material is different from that of the base material. The primary and secondary windings of a core transformer are interconnected by a mutual magnetic field conducted through the incomplete core and cladding thickness of the material being measured. The three legs of the core are made of ferromagnetic material and have an air gap between the two legs.
It has an incomplete U-shape. The flux path is completed by placing a flux-conducting cladding thickness material between the air gaps.

An alternating current voltage is applied to the primary winding of the core transformer. The primary and secondary windings of a core transformer are interconnected by a mutual magnetic field conducted through the incomplete core and cladding thickness of the material being measured. The magnitude of the voltage induced in the secondary winding depends on the magnitude of the voltage applied to the primary winding, the ratio of the number of turns in the secondary winding to the number of turns in the primary winding, and the reluctance of the magnetic flux path.

The ratio of the magnitude of the voltage induced in the secondary winding to the magnitude of the voltage applied to the primary winding is a non-destructive measure of the thickness of the cladding material. The turns ratio does not change. By normalizing the voltage induced in the secondary winding by the magnitude of the voltage applied to the primary winding, a voltage ratio is created that is independent of the magnitude of the voltage applied to the primary winding. In this way, the voltage ratio becomes independent of changes in the voltage applied to the primary winding. Once the turns ratio is known, the voltage ratio depends only on the reluctance of the magnetic flux path.

The reluctance of a ferromagnetic imperfect core is constant. The reluctance of the material to be measured is:
It depends on the composition of the cladding material, the thickness of the cladding material, and the composition of the base material. A predicted voltage ratio is obtained by each combination of these three variables, cladding material composition, cladding thickness, and base material composition. If the composition of the cladding material and the composition of the base material are known, the voltage ratio is a non-destructive measure of the thickness of the cladding material.

The thickness of the cladding material is determined by reference to a specific cladding material to base material voltage ratio chart based on a scale near the intersection of the voltage ratio and the composition of the cladding material. This cladding material to base material voltage ratio chart is constructed using a number of test blocks in which the composition of the cladding material, the thickness of the cladding material, and the composition of the base material are known. For a particular composition of the base material, the test block varies the range of cladding material compositions and the range of cladding thicknesses. The voltage ratio is recorded as each test block, one at a time, is placed between the air gaps of the incomplete core with voltage applied to the primary winding. The voltage ratio varies from zero to turns ratio.

The incomplete core is made by stacking flat U-shaped ferromagnetic stacks to a certain depth. The end of the incomplete core placed in contact with the cladding thickness material is tapered substantially perpendicular to any one plane of the laminate. The tapered end forms a V-shape with a straight line segment at the bottom of the stack. At the tip of the taper, a wear-resistant material is inserted over the entire bottom of the core to prevent wear of the laminate. This taper concentrates the magnetic flux where the imperfect core is in contact with the material whose cladding thickness is to be measured. The distance between the wear inserts establishes the specific length of the material to be measured for cladding thickness, through which the magnetic field is established. The depth of the incomplete core establishes the width of the magnetic field. All cored transformers intended for use with the same cladding material-base material diagram shall have the same distance between the wear inserts, the same depth of the incomplete core,
In addition, the V-shaped taper must be the same.

The preferred embodiment applies an alternating current voltage of known magnitude and frequency to the primary winding to induce a voltage in the secondary winding. The voltage applied to the primary winding is kept constant at a known value. This eliminates the need to normalize the voltage induced in the secondary winding by the voltage applied to the primary winding. The magnitude of the voltage induced in the secondary winding can be used directly.

The magnitude of the voltage induced in the secondary winding depends on the magnitude of the voltage applied to the primary winding, the ratio of the number of turns in the primary winding to the number of turns in the secondary winding, and the reluctance of the magnetic flux path. Among these, the magnitude of the voltage applied to the primary winding, the turns ratio, and the reluctance of the three ferromagnetic legs of the incomplete core are constant and do not change. The cladding thickness of the material being measured provides two parallel magnetic flux paths, each with a different reluctance. The equivalent reluctance of parallel magnetic flux paths depends on the composition of the cladding material, the thickness of the cladding material, and the composition of the base material. If the turns ratio varies depending on the combination of three variables: cladding material composition, cladding material thickness, and base material composition, and the voltage applied to the primary winding is known, then the secondary winding A predicted voltage is induced in . If the composition of the cladding material and the composition of the base material are known, the voltage induced in the secondary winding is a non-destructive measure of the thickness of the cladding material.

The thickness of the cladding material is determined with reference to a particular cladding material-base material diagram based on a scale near the intersection of the voltage induced in the secondary winding and the composition of the cladding material. A cladding-base material diagram is constructed using a number of test blocks in which the cladding composition, cladding thickness, and matrix composition are known. For a particular composition of base material, the test block varies the range of cladding composition and the range of cladding thickness. The voltage induced in the secondary winding is recorded when a known voltage is applied to the primary winding and each test block, one at a time, is placed between the air gaps of the incomplete core transformer.

Incomplete core transformers are useful for determining thicknesses up to half the distance between wear inserts.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram illustrating a cladding thickness measuring apparatus 10. As shown in FIG. Lead wire 50 connects primary winding 52 to an alternating current voltage source 96 and a voltage ratio calculator 98.

Primary winding 52 is shown surrounding a portion of incomplete core 54 . The voltage applied to the primary winding 52 causes a current to be generated in the primary winding 52 and the incomplete core 5
2 to generate a magnetic field. The flux circuit is completed by the cladding thickness measured material 56. This cladding thickness measured material 56 is a base material 58 having a base material thickness of 60.
and a cladding material 62 having a cladding thickness 64. Substantially all magnetic flux lines 66 pass through the incomplete core 54. To complete the magnetic circuit, lines of magnetic flux 66
The magnetic flux lines 68, which are part of the cladding material 62, pass through the cladding material 62. The remaining magnetic flux lines 70 of magnetic flux lines 66 pass through cladding material 62, base material 58, and again through cladding material 62.

The lead wire 38 connects the secondary winding 40 to the voltage ratio calculator 9.
It is connected to 8.

The voltage ratio calculator 98 provides a ratio of the magnitude of the voltage induced in the secondary winding 40 to the magnitude of the voltage applied to the primary winding 52. This voltage ratio is a non-destructive measure of the thickness 64 of the cladding material 62. Primary winding 52 has 300 turns and secondary winding 40 has 600 turns. The turns ratio is constant. By normalizing the voltage induced in the secondary winding 40 by the magnitude of the voltage applied to the primary winding 52, the voltage ratio becomes independent of the magnitude of the voltage applied to the primary winding 52. Made. In this way, the voltage ratio is not affected by changes in the voltage of voltage source 96.

For a known turns ratio, the voltage ratio depends only on the reluctance of the magnetic flux path. The reluctance of the incomplete core 54 is constant. The reluctance of the material 58 to be measured depends on the composition of the cladding material 62, the thickness of the cladding material, and the composition of the base material. The voltage ratio can be predicted by each combination of these three variables: the composition of the cladding material, the thickness of the cladding material, and the composition of the base material. If the composition of the cladding material 62 and the composition of the base material 58 are different, the voltage ratio will depend on the thickness 6 of the cladding material 62.
4 non-destructive measurement quantity.

The thickness of the clad material 62 is a special clad material.
Voltage ratio and cladding material 6 by referring to the base material voltage ratio chart
It is determined from the scale near the intersection with the thickness of 2. The cladding material-to-base material voltage ratio chart is shown in Figure 3 using the ordinate scale on the left for cladding stainless steel onto a carbon steel matrix over a range of ferrite numbers. . A cladding to base material voltage ratio chart is also constructed using a number of test blocks in which the composition of the cladding material, the thickness of the cladding material, and the composition of the base material are known. For a particular composition of base material, the test block measures over a range of cladding compositions and cladding thicknesses. The voltage ratio is recorded when voltage is applied to the primary winding and each test block is placed, one at a time, in the air gap of the incomplete core type transformer 54. The voltage ratio ranges from 0 to turns ratio.

FIG. 2 is a schematic diagram illustrating a preferred embodiment of cladding thickness measuring device 10 in which the voltage applied to primary winding 52 is constant. Lead wire 12 connects constant voltage output transformer 14 to an alternating current voltage source 16. Normally 60Hz AC voltage source 16 is 117 volts
It is rms. Constant voltage output transformer 14 absorbs voltage variations of AC voltage source 16 over a range of 105 to 130 volts to provide an output voltage 1 fixed at 117 volts rms.
Maintain 8.

Power supply 20 is a half-wave rectifier circuit that produces a constant DC output voltage. The primary winding of step-down transformer 22 is connected to voltage source 18 by lead 19 . An AC voltage of 12.6 volts is induced in the secondary winding of step-down transformer 22. A first lead of the secondary winding of step-down transformer 22 is connected to the anode of diode 24 .
capacitor 26, resistor 28, and capacitor 30
forms a π-type filter. The half-wave rectified voltage supplied to the π-type filter between the cathode of diode 24 and the second lead of the secondary winding of step-down transformer 22 is filtered and unnecessary before the DC voltage is applied to the load. ripples and voltage fluctuations are removed. Capacitor 26 is 25 microfarads, resistor 28 is 500
Ohms, capacitor 30 is 25 microfarads.

Zener diode 32 is connected in parallel with capacitor 30. Zener diode 32 has a small breakdown voltage of 9.1 volts due to residual ripple in the filtered voltage of capacitor 30. As a result, both ends of the zero adjustment potentiometer 34 are
The DC voltage is constant at 9.1 volts. Zero adjustment potentiometer 34 is a 10-turn 25 kilohm variable resistor. The voltage of the slider with respect to the common terminal of the zero adjustment potentiometer 34 is determined by the output voltage meter 3.
6. The second lead of the secondary winding of step-down transformer 22 is also connected to voltmeter 36 .
Voltmeter 36 can measure the effective true voltage. It is a digital voltmeter with a 3.5 digit display. Lead wire 38 connects secondary winding 40 to a voltage measurement terminal of digital voltmeter 36.

The primary winding of step-down transformer 42 is connected to constant voltage source 18 . The 6.3 volt AC voltage induced in the secondary winding of step-down transformer 42 is applied to three series resistors. The first current limiting resistor 44 is a 20 ohm resistor, the gain adjustment potentiometer 46 is a 10-turn 25 ohm potentiometer, and the second current limiting resistor 48 is a 20 ohm resistor. The lead wire 50 supplies the voltage between the slider pair common terminal of the gain adjustment potentiometer 46 to the primary winding 52 .

Primary winding 52 is shown surrounding a portion of incomplete core 54 . The voltage applied to the primary winding 52 causes a current to flow through the primary winding 52 and the incomplete core 5
Generate a magnetic field within 4. The flux circuit is completed by the cladding thickness measured material 56. The cladding thickness measured material 56 is a base material 58 with a base material thickness of 60.
and a cladding material 62 having a cladding thickness of 64. All magnetic flux lines 66 pass through the incomplete core 54. To complete the magnetic circuit, magnetic flux lines 66
Some of the magnetic flux lines 68 pass through the cladding material 62. The remaining magnetic flux lines 70 of magnetic flux lines 66 pass through cladding material 62, base material 58, and again through cladding material 62.

The incomplete core 54 is made of a laminated transformer core. All the laminates in the laminated core structure of the incomplete core 54 are U-shaped and the same. The uniform cross-sectional width of each of the three legs of the laminate is 0.9 centimeters (0.36 inches). The laminates are stacked to a depth of 0.9 centimeters (0.36 inches). The depth of the stacked laminates influences the gain and therefore the clad material-base material diagrams described below.

The incomplete core 54 consists of three legs of ferromagnetic material. A primary winding 52 having 300 turns is wound around the first leg. The handle 72 is attached to and insulated from the second leg of the incomplete core 54. A secondary winding 40 having 600 turns is wound on the third leg of the incomplete core 54. The end of the first leg on the side not connected to the second leg and the third
The ends of the legs form an air gap in the magnetic flux path and are tapered. This tapered end has a V-shape, and has a straight line segment in the center of the V-shaped end. This straight line segment is substantially perpendicular to all planes of each separate laminate. Cladding thickness measured material 5
6 is placed across the air gap in contact with the tapered end. To eliminate wear on the laminate,
An insert of material selected for its wear characteristics is inserted into the tapered end.An insert of material selected for its wear characteristics is inserted into the tapered end to form the wear element 74. Tungsten, 304 stainless steel, or Stellite inserts are used.

By tapering the ends of the first and third legs of the imperfect core 54 to form a direct line segment substantially perpendicular to the plane of the laminate, the imperfect core 54 has a cladding thickness coverage. The magnetic flux lines in the portion that contacts the measurement material 56 are concentrated. The distance between the wear inserts constitutes a specific length of the material 56 through which the magnetic field is generated. core 5
The depth of 4 corresponds to the width of the magnetic field. Wear element 74
The distance between them, distance 76, is 2.5 centimeters (1 inch). The cladding-base diagram described below is dependent on this distance, and all incomplete core transformers using this diagram must have the same distance between the tapered ends. To guarantee repeatability, all core transformers using the same cladding-base diagram must have the same V-shaped tapered end. The tapered end also facilitates cladding thickness measurements on the coated surface.

Unlike surface resistance measurements that involve passing a current through a material to determine its surface resistance, the present invention non-destructively determines the thickness 64 of the cladding material 62 by passing magnetic flux lines through the material 56. There is a particular thing.

The present invention connects the AC voltage source 18 to the step-down transformer 42.
and by applying an alternating voltage to the primary winding 52 through the gain adjustment potentiometer 46. While keeping the imperfect core 54 separated from the influence of the magnetic material, the zero adjustment potentiometer 34 is adjusted until the voltmeter 36, which measures the induced voltage in the secondary winding 40, reads zero. Keeping the imperfect core 54 away from the influence of magnetic materials can be achieved by holding the imperfect core 54 in air away from the magnetic material, or by placing non-magnetic material in contact with the wear elements 74 between the air gaps. This can be done by leaving it in place. During zeroing, the permeance between wear elements 74 is minimal. Or, since reluctance is the reciprocal of permeance,
The reluctance to the magnetic field lines between wear elements 74 is maximum.

Gain is adjusted by placing a high flux conductive material, such as carbon steel, between the air gap of the incomplete core 54 in contact with the wear element 74. The magnetic permeability of the high flux conducting material must be at least the same as the permeability of the base material being tested. Gain adjustment potentiometer 46 is adjusted until voltmeter 36, which measures the induced voltage in secondary winding 40, reads 500 millivolts. Higher flux conductive materials provide lower reluctance to magnetic field lines between wear elements 74.

If the zero adjustment and gain adjustment are not independent, it is necessary to repeat the zero adjustment and gain adjustment several times. Zero and gain adjustments are made using the incomplete core 54.
a voltmeter 36 indicating the voltage induced in the secondary winding 40 when the secondary winding 40 is located away from the influence of magnetic materials;
and until the voltmeter 36, which indicates the voltage induced in the secondary winding 40 when the high flux conductive material is placed between the air gap in contact with the wear element 74, reads 500 millivolts. It can be done. It is not important that the value of the alternating current voltage applied to the primary winding 52 is known. the voltage applied to the primary winding 52 is constant;
and the voltage induced in the secondary winding 40 is zero when the reluctance is at a maximum between the wear elements 74 and when the reluctance is at a minimum between the wear elements 74.
All you need to know is that it is 500 millivolts.
Once these conditions are adjusted, the zero adjustment potentiometer 34 and gain adjustment potentiometer 4
6 need not be changed during use of the cladding thickness measuring device 10.

Once the above adjustments have been made, a test block of known cladding thickness, cladding material and base material is placed between the wear elements 74 of the incomplete core 54. The same voltage induced in the secondary winding 40 and indicated by the voltmeter 36 is recorded. Separate Tesro blocks having known cladding thicknesses, cladding materials, and base metals are placed between the wear elements 74 over a range of cladding material compositions and cladding material thicknesses to induce the cladding in the secondary winding 40. The resulting voltage is recorded. This results in a series of points for each test block. The test points are connected to form a curve. A clad material-base material diagram is obtained from a series of curves.

FIG. 3 shows a clad material-base material diagram in the case where stainless steel is clad to a carbon steel base material. Nine curves are shown. The cladding thickness was varied from 0 to 1.27 centimeters (0 to 0.5 inches). The composition of the clad material is indicated by the ferrite number, which varies from 0 to 16. Curves 78, 80, 82, 84, 86, 88, 90, 9
2 and 94 are respectively 0, 2, 4, 6, 8, 10,
Shown are clad materials with ferrite numbers 12, 14 and 16. Curves 78-94 cover the range of ferrite numbers commonly used in cladding manufacture. Clad material containing curves similar to curves 78 to 94 - Base material diagram is clad material -
Prepared for each change in base material combination.

Once the zero and gain adjustments have been completed and the cladding material-base material diagram has been prepared, the incomplete core 54 is inserted into the wear element 7 in contact with the cladding thickness measured material 56.
4 and the cladding thickness is placed on the material 56 to be measured. The voltage induced in the secondary winding 40 and indicated by the voltmeter 36 is recorded. The ferrite content of the clad material is determined using any known means. Once the ferrite numbers of the base material and cladding material and the voltage induced in the secondary winding 40 are known, reference can be made to the cladding material-base material chart similar to that shown in FIG. 3 for the base material. If the voltage induced in the secondary winding 40 is plotted on the ordinate, the cladding thickness is determined on the abscissa below the intersection of the voltage induced in the secondary winding 40 and the curve representing the ferrite number of the cladding material. read from the scale. It is necessary to enter an intermediate ferrite number.

The magnitude of the voltage induced in the secondary winding 40 depends on the voltage applied to the primary winding 52, the turns ratio between the primary winding 52 and the secondary winding 40, and the winding ratio between the primary winding 52 and the secondary winding. 40 and the reluctance of the magnetic flux paths interconnecting them. The voltage applied to primary winding 52 is determined when the gain adjustment is adjusted by potentiometer 46, and is maintained constant during testing. The primary winding 52 has a turns ratio of 300 and the secondary winding 40 has a turns ratio of 600. The turns ratio, ie, the ratio of the number of turns of the secondary winding 40 to the number of turns of the primary winding 52, is constant. The only variable is the reluctance of the magnetic flux path interconnecting primary winding 52 and secondary winding 40. The magnetic flux path consists of the three ferromagnetic legs of the incomplete core 54 and the cladding thickness of the material 56 to be measured.
The reluctance of the three ferromagnetic legs of the incomplete core 54 is constant. The reluctance of the material 56 to be measured depends on the composition of the cladding material 62, the thickness of the cladding material 64, and the composition of the base material 58.

A flux-conducting cladding material 62 of a particular magnetic permeability over a flux-conducting matrix 58 of a different magnetic permeability determines the cladding thickness between wear elements 74 of the material to be measured when placed between the air gaps of the incomplete core 54. 56. Two parallel reluctances are combined to form an equivalent reluctance. The equivalent reluctance of the cladding material to be measured 56 depends on the composition of the cladding material, the thickness of the cladding material, and the composition of the base material. Each combination of these three variables, cladding material composition, cladding material thickness, and base material composition, induces a predicted voltage in the secondary winding 40 that corresponds to the known voltage applied to the primary winding 52. . The relationship between these variables is represented graphically in the clad material-base material diagram of FIG. Thus, given the composition of the cladding material 62 and the composition of the base material, the voltage induced in the secondary winding 40 is a non-destructive measure of the cladding material thickness 64.

When using the clad material-base material diagram of FIG. 3, the composition of the clad material is determined by the ferrite number.

Cladding materials up to 0.054 centimeters (0.025 inches) thick have been applied to base metals ranging from 10 to 25 centimeters (4 to 10 inches). In these applications, the thickness 60 of the base material 58 is
It had no effect on the voltage induced at zero.

A partial core transformer is useful for determining the cladding thickness up to half the distance 76. It is recommended that incomplete core transformers be used to determine the cladding thickness to only 1/4 of the distance 76. To measure thinner cladding material, a partial core transformer should be constructed with a larger distance 76.

Sensitivity improvement can be achieved by increasing the turns ratio. Of course, this corresponds to the corresponding cladding material.
A base material diagram is required.

Prior to measuring the thickness of the cladding material, flaws such as cracks in the cladding material 62 are generally detected.
Therefore, it is not necessary to check the influence of flaws during operation of the cladding thickness measuring device 10.

It is generally appropriate to spot inspect the machined and polished cladding to determine the thickness of the cladding material. However, it is also possible to establish a grid over the workpiece and take the cladding thickness from each square of the grid.

The cladding thickness measuring device 10 has been described for application where the cladding material is bonded onto a base material and the magnetic permeabilities of the cladding material and the base material are different and relatively high. The cladding thickness measuring device 10 is also suitable for measuring cladding thickness when the magnetic permeability of the cladding material is considerably lower than that of the base material, such as when measuring the thickness of paint on a metal base material. can also be used. In applications where the permeability of the cladding material is considerably lower than that of the base material, the cladding thickness measuring device 10 measures the cladding thickness, such as when the permeability of both the cladding material and the base material are relatively high. It has been found to be effective over approximately the same range of

[Brief explanation of the drawing]

FIG. 1 is a side view of a partially cored transformer showing the electrical circuit diagram associated with the partially cored transformer and typical magnetic flux lines through the wear insert, cladding material, and base metal; Figure 2 shows an embodiment of the present invention when the voltage applied to the primary winding is constant, and Figure 3 shows a case where there is a stainless steel cladding on a carbon steel base material within the range of ferrite numbers. This is a specific cladding material-base material chart showing the relationship between secondary winding induced voltage and cladding thickness due to a 1 inch air gap. 10... Cladding thickness measuring device, 14... Constant voltage output transformer, 20... Power supply, 34... Zero adjustment potentiometer, 36... Voltmeter, 40... Secondary winding, 46... Gain Adjustment potentiometer, 5
2...Primary winding, 54...Incomplete core, 58...
Base material, 62... Clad wood.

Claims (1)

[Claims for Utility Model Registration] 1. A constant voltage AC power source, a first terminal having a first terminal, a second terminal, and a voltage dividing terminal, the first terminal and the second terminal being connected to the constant voltage AC power source. A pressure vessel, a partially wound primary winding, a partly wound secondary winding, and a tapered first winding.
a core having first and second spaced apart legs having an end and a second end, the apex of the taper having a length substantially the depth of the core and perpendicular to the plane of the core; The material whose cladding thickness is to be measured is brought into contact by forming a straight line segment with an incomplete transformer core in which two straight line segments are provided to establish a magnetic field over a specified length and width in the material of which the cladding thickness is to be measured; and the voltage divider terminal of the first voltage divider. and said second
means for connecting a terminal to the primary winding of the incomplete transformer core; means for supplying a constant DC voltage; a second voltage divider having two terminals connected to the means for supplying the constant DC voltage; a voltage measuring means; the voltage dividing terminal of the second voltage divider and the second voltage divider;
means for connecting a terminal to the voltage measuring means for supplying power thereto; and means for connecting the secondary winding to the voltage measuring means, the voltage measuring means being configured such that a voltage is applied to the primary winding. and the voltage induced in the secondary winding when a magnetic flux conductive clad material on a magnetic flux conductive base material having different magnetic permeability is brought into contact with the first end and the second end to complete a magnetic flux circuit. 1. A cladding thickness measuring device for determining the thickness of a magnetic flux conducting cladding material on a magnetic flux conducting base material having different magnetic permeability, characterized by measuring the thickness of the magnetic flux conducting cladding material on the magnetic flux conducting base material having different magnetic permeability. 2. A wear-resistant insert according to claim 1, wherein a wear-resistant insert is inserted at the tip of the tapered end.
A cladding thickness measuring device that determines the thickness of flux-conducting cladding materials on flux-conducting base materials with different magnetic permeabilities. 3. Claim 1, characterized in that the magnetic permeability of the magnetic flux conductive base material is greater than the magnetic permeability of the magnetic flux conductive cladding material.
A cladding thickness measuring device for determining the thickness of a flux-conducting cladding material on flux-conducting base materials having different magnetic permeabilities as described above.