对直径为1 400 mm的大型复杂钛合金机匣进行渗透检测时，使用静电喷涂法施加渗透液，可使渗透液覆盖机匣全表面，无多余渗透液淤积，清洗时间减少，背景良好，缺陷显示结果可靠。检测中结合黑光光源，使用工业内窥镜可以拓宽渗透检测过程中人眼目视可达的区域范围。选择工业内窥镜探头时，应根据腔体大小及缺陷部位，保证测量光照条件（与待检表面距离合适），才能得到较清晰的缺陷显示，从而提高判定的准确性与可靠性。

For the penetrant inspection of large titanium ally casing with a diameter of 1 400 mm,the electronic spraying method can make the penetrant cover the entire surface with unnecessary liquid penetrant deposition. This method reduces the cleaning time,obtains an acceptable background and reliable defect indications. Combining black light source with industrial endoscopy can widen the reachable area of human vision in the process of penetration detection. The selection of the industrial endoscope lens used in the inspection should be based on the cavity size, the defects location and the proper lighting conditions (with suitable distance apart from the surface to be inspected) in order to obtain the clearer indication of defects and improve the accuracy and reliability of the judgment.