The LUBRImini is a measuring instrument for the determination of the oil layer thickness on metallic surfaces. The functional principle is based on the determination of fluorescence. Therefore a special characteristic of oil and other organic materials is used.

In contrast to metals, organic materials emit radiation after excitation with a defined wavelength. The intensity of this radiation is dependent on the amount of the lubricant being excited. The measurement is based on sensitive single photon counting techniques. In addition, a compensation of the ambient light is integrated. The compact design and the built-in rechargeable battery allow a mobile use.