This regime may be considered as intermediate between regime of constant force and constant height, when velocity of adjustment of feedback follows the slightly sloping variations of relief and does not follow the strongly sloping variations. Then at the time of intersection of small nonuniformity scanning will be at constant height of scanner. As a result of the slightly sloping variations will be weakly contrast and the strongly sloping variations - sharp contrast. It may be useful for finding of small nonuniformity on large field on background of big flat relief features. In that case contrast increase with increasing of velocity.
Optimal parameters select for each case separately.
Contrast image is typical for phase signal because phase displacement between exciting oscillations and quartz response depends upon properties of surface. Due to this property the phase detection microscopy may be used for making of graphical mapping such properties as elasticity, adhesiveness and friction. Force modulation regime may be used as means of study of elastic properties of sample because quartz response in that case depends upon these properties. Choice of parameters in Shear-Force mode is very important. If big Spnt value is used then fiber interact with surface strongly hence amplitude of oscillations violently decrease and image quality become worse.