What methods can be used to reduce the measurement error of a Leeb hardness tester?

Taiwan Nakazawa Co., Ltd. answers for you:
1. For hollow materials such as pipes, try not to impact the cross-section on the side; alternatively, adding a support inside the pipe wall is difficult but very effective. When measuring solid pipes with a curved surface diameter of 20mm-100mm, a curved surface support ring must be selected.
2. For thin plates, the thickness should be above 5mm (try not to choose a hardness tester for workpieces below 5mm). When measuring, grease should be applied evenly on the back of the measurement site to achieve dense coupling with the platform, pressing out the air in between so it cannot move. Do not apply too much grease.
3. Ensure the surface finish of the metal material has an RA of less than 7um; the better the surface finish, the higher the accuracy of the hardness value.
4. For solid cylinders, to ensure the stability of the workpiece, a V-shaped anvil should be added for smaller cylinders.
5. When measuring hardness, efforts should be made to improve the surface roughness, weight, and degree of coupling of the workpiece. If the surface roughness is poor and difficult to process while the workpiece is large, select a G-type impact device.