... closed-loop force sensor control system 10 class Test force selection, 14 class test scale robust construction, good rigidity, accurate, reliable ... flat precision measurement3. Main accessories Big flat test bench: 1 setSmall flat test bench: 1 setV-shaped test bench: 1 setSteel ball indenter: Φ2.5 ... microscope: 1 set4. technical data Measuring range: 4-650HBW Test force: 612.9, 980.7, 1225.9, 1838.8 ...