Endoscopic inspection of heat exchangers boiler tube is the very basic but critical method in NDT application filed. In this case, engineers need to analysis tube wall etching condition related to their lifecycle. Thus, the “depth data” of certain etching caves on certain area of tube sections are incredibly important! The new X3000 3D measurement video scope acts a practical helper in this case…
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Front view:
Benefit from the 95o wide angle field of view and new high illumination fiber and light source, the front view image provide efficient searching jobs to find out the target defects’ location.
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Side view:
When the etching cave areas are found, engineer switches the view angle to side to get close-up view for details. Owes to fluid dynamics, some normal etching are concentrated but some abnormal spot exist independently. Those are target of this inspection project.
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Measurement results:
Conventionally, people need to withdraw the probe, change a side view measurement lens, then get back again into the tube again. Benefit from the exclusive “Dual-3D measurement” design of X3000, the engineer just hold the probe, hired the 3D capture process in ten more seconds, and then got every defects’ 3D models for advance analysis.
In this case, the “Depth” measurement may apply “point-to-plane” or “point-to-line” measure tools that depend on the relation condition of the surface and caves.
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Target defects |
Test value |
Known value |
|
| 1 |  |
0.31 | 0.312 |
| 2 |  |
0.54 | 0.453 |
| 3 |  |
0.17 | 0.178 |
| 4 |  |
0.96 | 0.944 |
| 5 |  |
0.59 | 0.677 |
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Measurement challenges & tips:
In conclusion, the true challenges are the surface condition of the tube wall. In some area, the red coating remains well then it would be a failure factor of traditional stereo technology and hard to take qualified 3D images. In some other areas, the etching causes the surface nears to high reflective and it may lead fail results if use structure light scans technology.
By our active stereo method, adopt the exposure value and light volume fine tune, it’s easier to operate and get rid of frustrating reworks. The Dual view & 3D measurement optical design provides big value of time saving inspection tasks!