The DMS 2 A-Scan thickness gauge has the capability of performing "AUTO-V" thickness/velocity measurements. The instrument uses the patented (U.S. Patent No. 6,035,717) TopCOAT probe and can make automatic measurements on uncoated materials. A benefit is the elimination of calibration blocks made of different materials. Because the unit automatically measures the material velocity, calibration to a material standard is not required. It also allows users to accurately measure the thickness of materials when the actual material properties are unknown.