When I used to work in a Shipyard Pipe shop, nothing I have ever found showed the quality of the inside of a straight pipe like a 5mw red laser (I have much more powerful ones, and green but they are too bright for this).
The polerised light pointed into the tube towards the side a bit shows reflective patterns all the way down as it goes through the pipe.
I got to be sort of an expert in reading those patterns to determine which pipes were likely to cause me problems on pipe bending machines where a mandrel is held near the bend point on the interior of a pipe and the pipe slides past it as it bends around a die. For some materials (and some chinese manufacturers) it was a chore to not bust a pipe or a mandrel tip.
Some of the pipes had manufacturing defects (fine for water but not for bending) that were almost impossible to detect from the inside or outside with any kind of light, but with the highly polerized laser light you could actually see the bulges or lop-sidedness amplified in the patterns and skip the risky stock. a non polerised light such as a flashlight or even a borescope wouldn't show the web like patterns that were full of information to the discerning eye.
It was a skill and technique I discovered by screwing around to be honest, but after I started to check all my pipes that way a few other guys started to do it as well. For all I know this technique is still being used. Your not looking at the bright reflection, but the weaker ghosting patterns that seem to show the surface texture and roundness amplified quite a bit.
I also just like the tech. of lasers, I've always been fascinated by handheld size lasers. It's truley amazing how far we have come.
The polerised light pointed into the tube towards the side a bit shows reflective patterns all the way down as it goes through the pipe.
I got to be sort of an expert in reading those patterns to determine which pipes were likely to cause me problems on pipe bending machines where a mandrel is held near the bend point on the interior of a pipe and the pipe slides past it as it bends around a die. For some materials (and some chinese manufacturers) it was a chore to not bust a pipe or a mandrel tip.
Some of the pipes had manufacturing defects (fine for water but not for bending) that were almost impossible to detect from the inside or outside with any kind of light, but with the highly polerized laser light you could actually see the bulges or lop-sidedness amplified in the patterns and skip the risky stock. a non polerised light such as a flashlight or even a borescope wouldn't show the web like patterns that were full of information to the discerning eye.
It was a skill and technique I discovered by screwing around to be honest, but after I started to check all my pipes that way a few other guys started to do it as well. For all I know this technique is still being used. Your not looking at the bright reflection, but the weaker ghosting patterns that seem to show the surface texture and roundness amplified quite a bit.
I also just like the tech. of lasers, I've always been fascinated by handheld size lasers. It's truley amazing how far we have come.
I use 5mW green lasers for presentations and for business gifts.
