| 摘要 |
PURPOSE:To improve flaw detection conditions and make detection performance accurate by detecting the concn. of magnetic particles with a luminance meter, and maintaining the concn. of magnetic particles constant. CONSTITUTION:Magnetic particle liquid 2 of a prescribed concn. of magnetic particles is contained in a magnetic particle liquid tank 1, and is being stirred by a stirrer 3. A pump 4 lifts the liquid 2 to above a material 7 to be inspected through a liquid feed pipeline 5 and a liquid feed valve 6, and sprays the liquid 2 conducted to a spray port 8 onto the surface of the material 7. Thereafter, the sprayed liquid 2 is collected by a liquid collecting and receiving tray 9 and an inclined floor surface 10, and is recirculated to the tank 1. On the other hand, the liquid 2 in the tank 1 is sampled and fed via a pump 14 to a luminance meter 15, by which its concn. is detected from luminance. Magnetic particle liquid 17 of high concn. is contained in a tank 16, and is being stirred by a stirrer 18. When the concn. of the magnetic particles in the tank 1 lowers below the prescribed concn., the liquid 17 is additionally supplied from the tank 16 into the tank 1 automatically at a constant rate by way of a pump 19 based on the detection signal of the meter 15. |
