do they have lasers...?
07-24-2007, 07:20 AM
#1
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Join Date: Sep 2003
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So yesterday we were supposed to start training on a $130,000+ PIV,PLIFF system which uses a laser and two cameras.
Problem 1: the test section, where the laser will shine and the cameras will be viewing, was thrown together in a rush by the graduate student that I work under the day before. Soooo... the paint on on part of it wasn't dry and it leaked in several places. Epoxy up the leaks, and the paint bleads off into the system causing really psychadelic metalic colors of bronze red green and pink depending on how you look at it. This paint which is now in our entire system will absorb the laser wavelength and emit it at a frequency that is close to what the cameras will be viewing, so our cameras will basically be saturated by the paint and we won't be able to see anything.
Problem 2: camera number two does not respond, and will not be read by the computer system. The technician here to train us tries to trouble shoot the problem for several hours, is unable to, so now he is stuck training us in 2d. And he will have to service either the camera, camera pack, or computer and return it to us working.
Problem 3: most commercial lasers of this sort, actually have two lasers that pulse out of phase. Laser number two does not respond and does not pulse. Our system can't take multiple pictures in phase without laser 2. Technician tries to troubleshoot the problem, but since the lasers are from another company, the technician's company packages the laser, camera, computer etc, to work together, he does not know how to work on it or how to service it.
So yesterday as we were supposed to be trained to use the PIV system we tried to troubleshoot all day. Today we were supposed to be trained to use the PLIFF system, but since nothing works, I'm led to believe we will be trying to get the laser working all day. But no one is here except me.
- Hand
Problem 1: the test section, where the laser will shine and the cameras will be viewing, was thrown together in a rush by the graduate student that I work under the day before. Soooo... the paint on on part of it wasn't dry and it leaked in several places. Epoxy up the leaks, and the paint bleads off into the system causing really psychadelic metalic colors of bronze red green and pink depending on how you look at it. This paint which is now in our entire system will absorb the laser wavelength and emit it at a frequency that is close to what the cameras will be viewing, so our cameras will basically be saturated by the paint and we won't be able to see anything.
Problem 2: camera number two does not respond, and will not be read by the computer system. The technician here to train us tries to trouble shoot the problem for several hours, is unable to, so now he is stuck training us in 2d. And he will have to service either the camera, camera pack, or computer and return it to us working.
Problem 3: most commercial lasers of this sort, actually have two lasers that pulse out of phase. Laser number two does not respond and does not pulse. Our system can't take multiple pictures in phase without laser 2. Technician tries to troubleshoot the problem, but since the lasers are from another company, the technician's company packages the laser, camera, computer etc, to work together, he does not know how to work on it or how to service it.
So yesterday as we were supposed to be trained to use the PIV system we tried to troubleshoot all day. Today we were supposed to be trained to use the PLIFF system, but since nothing works, I'm led to believe we will be trying to get the laser working all day. But no one is here except me.
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07-24-2007, 09:13 AM
#4
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Originally Posted by Baldy' post='878387' date='Jul 24 2007, 08:29 AM
I know what a camera is, what paint is, and what a laser is, and I still have no ******* clue what you're talking about.
Laser pulses a beam at a wavelength of 532 nm, the particles in the setup absorb this beam and re-emit it at a wavelength of 570 nm. The cameras have lenses to block out the 532 nm wavelength, so they will see the 570 nm wavelength of the particles. The paint was supposed to reduce the laser light from scattering, instead it is now in suspension and will emit a wavelength close to that of the particles. So it's like pointing a camera at the sun and taking a picture, we won't be able to see the particles, which is the whole point of this laser-camera system.
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07-25-2007, 08:27 AM
#8
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Was shown a little on how the one camera worked without any PIV or PLIFF running. Put our zoom lenses on, we can zoom in to a size that is half a brick on the pyramid on the back of a dollar bill. With 2000 pixels of resolution that's close!! So laser and laser computer are being shipped back to Germany today, and the cameras and camera computer are being shipped back to Michigan today. And we are finalizing desings for the new test section, with a removable top. At least we are getting something done. But our trip to Scotland for the UK Heat Transfer Conference is off, that sucks.
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07-25-2007, 09:41 AM
#10
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Originally Posted by toplessFC3Sman' post='878456' date='Jul 25 2007, 09:59 AM
That was with one camera in 2d? Does the second camera give any additional resolution, or just allow you to map in 3d?
The second camera has the same resolution. When we look in stereo we will be able to get 3d mapping for both PIV and PLIFF. So we can look at the full boundary layer.
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