如何计算阴极剥离测试结果中的等效直径

zblhx84

在ISO 20340-2009中，关于经阴极剥离试验后结果的评价，有以下描述：
Cathodic disbonding in accordance with ISO 15711:2003, method A
Immediately before the qualification test, form an artificial holiday (steel substrate totally exposed) of diameter 6 mm, using the procedure specified in method A of ISO 15711:2003.
After the qualification test, use a sharp, thin-bladed knife to make two radial cuts at 45° to each other through the coating, intersecting at the centre of the holiday. Cut the coating down to the steel substrate. Attempt to lift the coating with the point of the knife. Record the total area now exposed (including the area of the holiday). Calculate the disbonded area as the difference between the total area exposed and the area of the holiday.
From the disbonded area, calculate the corresponding equivalent diameter.
The equivalent diameter of the disbonded area shall be not more than 20 mm.

这里面提到，记录全部剥离面积（area），包括人工孔面漆。计算整个剥离面积和人工孔面积的差异；然后计算相当的等效直径（ the corresponding equivalent diame）。剥离面积的等效直径不应超过20 mm。

想问一下，这个相当的等效直径应该如何计算呢？

wangzhuang

您可以用图片处理软件，分别截取漏涂孔和剥离区域，因为漏涂孔的实际面积是知道的A=πR2=3.14*3*3=28.26 ，然后就可以根据漏涂孔和剥离区域的比例就能知道等效的剥离面积，然后换算到等效直径。