The ltm (layer thickness measurement) is a tool that Soft Imaging System Corp. has added to its analySIS software. The company says it determines layer thickness of porous or compact coatings and provides precise measurement of crack width. It tracks a crack's contour and provides calculated data results. It measures layer thickness of single and multiple coatings for a cut specimen using the neutral fibers concept. With neutral fibers defining the direction, each measurement is executed perpendicular to them. Straight lines, curves or circles can be neutral fibers, so complex coating structures and any modeled surfaces can be evaluated.