Application Note 002
操作说明002
Inspection of rubber lined metal pipes or vessels for disbonds
检测管道腐蚀或容器与其内衬橡胶脱胶

Motivation: Many metal pipes or vessels have rubber or other linings on the inside diameter for
transport or mixing of certain fluids. There is a common requirement to be able to inspect the bonding
between the metal and liner.
案例：许多金属管道或容器里有橡胶或其它内衬用以混合液体，一般需要检查金属和内衬橡胶之间的结合。

Principle: By using a transducer that can penetrate the rubber through the bondline, the amplitude of
the interface can be measured with a flaw gate. Good bonding will attenuate the signal. A disbond will
return a higher amplitude echo since the sound cannot now penetrate the rubber.
原理：我们需要选用一个能穿透（良好胶接口下的）橡胶的探头，然后利用缺陷闸门检测回波的波幅。良好
的胶接口会令信号衰减。在脱胶的地方由于声波没法穿透空气，会有较高幅度的回波反射。

Challenge: Initial tests with a 5MHz tranducer showed that we did not penetrate the rubber since a
known disbond was not resolved. Therefore a lower frequency 2.25MHz was used with a composite
construction to give better penetration and an improved signal to noise ratio. A dual-element was also
required because of the curvature of the pipe; a single element was too sensitive to rocking of the
transducer.
分析：起初我们使用5MHz的探头，由于声波没法穿透橡胶，因此工件上已知的脱胶部位无法显示出来。
因此我们使用频率**点的2.25MHz探头，能穿透橡胶和改进了信噪比。另外由于管道有弧度，所以
需要使用双晶探头。因为单晶探头无法消除盲区。

Solution:
· Raptor Imaging Flaw Detector
· RCA-10 or RCA-18 scanner
· Dual-element 2.25MHz composite transducer (1/4”) Part No. AE07E06
方案：
1.Raptor成像探伤仪
2.RCA-10或RCA-18扫查器
3.双晶2.25MHz探头，编号：AE07E06


Results:
结果：

Figure 1. C-scan of pipe. Initial results using 5MHz dual-element. Variable shows % flaw gate height.
图1 C-扫描管道。初步结果使用5MHz的双晶探头。不能明确显示已知脱胶位置。

Figure 2. C scan of pipe using 2.25MHz transducer. Variable shows % flaw gate height.
图2 使用2.25MHz的探头。可明显看到回波幅度较大位置代表脱胶位置。

Conclusion: Pipes and vessels with bonded internal liners can be inspected for disbonds automatically
using the Raptor and RCA-10 or RCA-18 and a low frequency composite dual-element transducer.
结论：使用Raptor,RCA-10或者RCA-18扫查器和低频双晶探头，可自动检测管道
和容器与其内衬的脱胶。