AFM measurements are limited by the shape of the tip used to probe the sample surface. As the tip wears, the finite size of the AFM tip may not allow the tip to accurately probe narrow or sharp features on a sample, resulting in underestimation of surface roughness and/or rounding/broadening of sharp surface features. For this reason, it is generally desirable to discard a tip when it is no longer sufficiently sharp. This has traditionally been a judgment requiring significant AFM experience.