The Leeb hardness also commonly known as Equotip hardness tester is a modern version of the Scleroscope. A hard metal ball (plunger) is struck at the test surface at a known velocity and an electronic sensor in the probe measures the rebound velocity of the plunger. The Leeb value is the ratio of plunger’s rebound velocity divided by the impact velocity times the constant number (1000). The resultant Leeb hardness values can be related to Rockwell, Brinell or Vickers hardness values using a standard correlation curve.
Most of the modern machines can indicate hardness values directly into the required conventional hardness scales. Leeb testers can be used at different angles as long as they are perpendicular to the test surface. The primary limitations of this test method are that the test surface must have a good surface finish, the minimum thickness as specified by the manufacturers.