辅助动力装置（APU）是指航空器上主动力装置（发动机）之外可独立输出压缩空气或供电的小型辅助动力装置，一般是小型的燃气涡轮发动机。对其零件进行渗透检测时，在液滴落过程中，零件悬空暴露在低温环境下。低温会加大液体的黏度，影响渗透液渗入缺陷和从缺陷中渗出，进而影响渗透检测的效果。对此问题进行了分析，并提出了简单的解决方案。

Auxiliary power unit (APU) refers to a small auxiliary power unit that can independently output compressed air or supply power except the main power unit (engine) on the aircraft. It is generally a small gas turbine engine. When performing penetration inspection of its parts, during the dropping process, the parts are suspended and exposed to low temperature,which will increase the viscosity of the liquid and affect the penetration and exudation of the penetrant from the defect,and then affect the penetration inspection result. This article makes a simple analysis of this problem, and puts forward a simple solution to solve the problem.