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. O buraco central: diâmetro 31,8 mm Diâmetro de defeito artificial: diâmetro 1,78 mm Distância de superfície: 1,78 mm-21,34 mm
O diâmetro do buraco e o tamanho do centro do buraco a partir da borda exterior:
| Furo | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diâmetro / polegada | 1.8 polegadas (todos os buracos) | |||||||||||
| Distância entre o buraco e a borda / polegada | 1.8 | 3.6 | 5.4 | 7.2 | 9 | 10.8 | 12.6 | 14.4 | 16.2 | 18 | 19.8 | 21.6 |