9 Material testing instruments and machines, namely, durometers; metal testing machines, namely, machines used to test the hardness and measure the impact resistance of metal, nonferrous metal and nonmetal to plastic, compressive and tensile deformation; microhardness testers; torsion testers; metal compression testing machines; metal hardness testing machines; plastic testing machines; metal strength testing machines; instruments for testing metals, namely, electronic apparatus for testing hardness, torsion testers, metal traction testing machines and metal compression testing machines; apparatus for testing microhardness, namely, microhardness testers; resistance measuring instruments; non-destructive testing apparatus, namely, metal, industrial materials, and plastic material hardness testers and microhardness testers; portable test apparatus, namely, portable hardness testers for ferrous metal, non-ferrous metal and plastic materials; sensors for measuring distance, chemical levels in aqueous solutions apparatus, not for medical use; scanning probe microscopes