Surface Roughness test

Surface Roughness Test gives a measure of micro-irregularities of a surface. Our laboratory is equipped with a digital portable tester: it is useful for example to measure the roughness of a wet surface which needs a high finishing quality because of hydro-dynamic reasons (ex. foils).
Amplitude parameters which characterize the surface are based on the vertical deviations of the roughness profile from the mean line. For example, Ra is the arithmetic average of the absolute values of surface variations inside the measured length and Rq is the root mean square of surface variation. Another important parameter is Rt : the maximum height of the surface profile.