DC ring standard test block(Type B test block for magnetic flaw detector) For DC and three-phase full wave Type B test block (also known as 12-hole DC test ring) is used to verify the comprehensive properties of magnetic powder when the magnetizing current is direct current or three-phase full wave current. Center Hole: diameter 31.8mm Artificial defect diameter: diameter 1.78mm Surface distance: 1.78mm-21.34mm
The diameter of the hole and the size of the hole center from the outer edge:
| Hole | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diameter / inch | 1.8 inch (all holes) | |||||||||||
| Distance of hole and edge / inch | 1.8 | 3.6 | 5.4 | 7.2 | 9 | 10.8 | 12.6 | 14.4 | 16.2 | 18 | 19.8 | 21.6 |