Coating thickness

Textfeld: 130
Textfeld: 0
Textfeld: 65
Textfeld: 260
Textfeld: 520
Textfeld: f = 5 kHz
Textfeld: Coating
Textfeld: Aluminium

D) Calibration curve

1. Put the probe on a slot-free spot of the BK1 and balance the system!

2. Shift the point and the grid close to the upper left corner!

3. Put 6 sheets of paper between the probe and the bulk!

4. Adjust the gain and the phase so that the point is located close to the lower right corner!

5. Put the probe consequently on stacks from 0 to 6 layers thickness and mark the spots using the tip-marker. Manually read out the co-ordinates of the point (Extended-Tab Mixer) into an Excel®-spreadsheet!

6. Calculate the distance between the point and the grid origin according to the co-ordinates!

7. Calculate a regression for the distance values according to the real stack thickness and draw the curve.

A) Job

1. Make a calibration curve showing the eddy current signal versus the real coating thickness!

2. Evaluate the thickness of an unknown coating using the calibration curve!


B) Utensils

1. EddyCation BK1, slot-free spot

2. Absolute probe

3. 6 sheets of paper

4. Micrometre gauge (accuracy 10 µm)


C) Restriction

1. Inspection frequency high enough to prevent the magnetic field from penetrating the bulk completely!


E) Evaluation of an unknown coating

1. Put a stack of unknown thickness between the probe and the bulk, mark the point in a different colour and calculate its distance from the origin.

2. Use the calibration curve for estimating the thickness of the stack: 1st analytically, 2nd graphically and compare the result to the real thickness!

F) Report

1. EddyCation report with all measurements.

2. Excel file including the spreadsheet, the function and the curve.

3. Result of the assessment and failure discussion.


Insulator on aluminium

Eddy current inspection with EddyCation






Classic surface


Compact surface


Coin rejection




Cracks (abs. probe)


Cracks (diff. probe)


Wall thickness