Profilometry:
Many times it is necessary to measure the surface roughness or topography in order to predict how a surface will perform in given conditions or to quantify wear resulting from experiments. This can be accomplished with profilometry. A profilometer has a stylus that traces the surface under study while the deflection is measured through a laser setup, as depicted below.
Tencor P-15 Profilometer
A few of the tips used for the stylus are shown below for (a) contacting, and (b) tapping modes.
(a) 
(b) 
It can be seen how the tip size will “read” the surface differently with different tips.
A Digital Instruments Nanoscope MultiMode AFM (atomic force microscope) is shown below. This device can perform the scans mentioned above; it can also perform nano-scratch and nano-indentation experiments.
Digital Instruments Nanoscope MultiMode AFM