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 currentسوراخ مرکزی: قطر 31.8mm قطر نقص مصنوعی: قطر 1.78mm فاصله سطح: 1.78mm-21.34mm
قطر سوراخ و اندازه مرکز سوراخ از لبه بیرونی:
| سوراخ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| قطر در اینچ | 1.8 اينچ (همه سوراخ ها) | |||||||||||
| فاصله سوراخ و لبه / اینچ | 1.8 | 3.6 | 5.4 | 7.2 | 9 | 10.8 | 12.6 | 14.4 | 16.2 | 18 | 19.8 | 21.6 |