In order to enable energy transfer and low friction in the mutual movement of various components in dynamic mechanical systems, these consist of contacts. Due to the small contact surfaces, high pressures occur there, so they need to be lubricated. Most contacts operate in the ElastoHydroDynamic (EHD) lubrication regime. There are many methods to measure the thickness of the lubricating film, but in our bachelor work, we will use colour optical interferometry, which is based on a contact between a steel ball and a glass plate. We used RGB colour space. Our goal was to write a program code that calculates the thickness of the lubricating film for any colour interferogram. In the beginning, we analysed interferograms, generated with light with unlimited coherence, then with limited coherence, and then we added detector noise to the limited coherence interferogram to get as close as possible to real interferograms. With the help of two-beam interference, we generated colour interferograms of the contact for all three cases when the static contact was loaded with 20 N. With the interferogram, where we take into account that the wave coherence is limited and has added noise, we made a calibration curve. The curve was used to calculate the thickness of the gap outside the contact for the colour interferogram generated with an unknown load. With the help of the thickness, we then determined the load with which the contact was generated.
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