Impact Brinell hardness meter as shown in Figure 1. Instrument is a small, simple device, device with a spring, a spring compression and release mechanism, device end with a steel ball. Test, the devices slow down, spring is compressed first, and then was released, the impact ball pressed into the surface of the specimen, specimen surface indentation. Indentation diameter is measured with a reading microscope, look up table, get the Brinell hardness value. National metrological verification method of JJG870-1994 provides for this kind of instrument.
This structure is simple, easy to use, cheaper. But force is not certain, large errors, accuracy of ± 8%. Instruments can be applied on Brinell hardness measurement accuracy requirement of situations. Because this instrument is too old, its stability than hammering Brinell hardness tester, at the production site has very little use.