7
2 Structure Feature &Testing Principle
2.1 Structure Feature
2.1.1 The Hardness Tester Appearance
1
LCD display
2
Main unit
3
USB Port
4
Impact device
5
Battery compartment cover
6
Product label
7
Keypad
2.1.2 D Type Impact Device
1
Support ring
2
Impact body
3
Coil unit
4
Guide tube
5
Loading tube
6
Release button
