a process and device for the quantifiable assessment of the physiological impression of reflective surfaces using a point source of light , whose light reflected by the measured surfaces is captured by a photodetector . a series of measured surface values are derived from these measured brightness values for a number of measuring points , which have an exactly defined separation , for which a number of preceding and following measured brightness values are each taken into consideration . the wavelength of the surface disturbances can thereby be determined and analyzed . at least one quality index is derived from the determined measured surface values for the evaluation of the respective surface . the device can be constructed as a hand - held device and moved manually over the surface being tested . for this purpose , the device has at least one measuring wheel , which is rotated by the contact with the surface and whose rotational movement is used to determine the individual measuring points .