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#1
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The convention mentioned (Protocol IV)
I believe you mean, "alluded to," "inferred" or "referenced," because I did not mention any convention beyond the Geneva Convention. does not prohibit non-eye-safe lasers on the battlefield. I've heard that on this forum. I cannot state authoritatively the reason that my employer told me something different than you are telling me. It does prohibit the building of specific use laser devices to intentionally blind people or use an existing device to intentionally blind people. It does not cover the accidental blinding of personnel as a result of the legitimate use of a laser device (ie rangefinding or target designation). In any event there are only 79 countries that have ratified the protocol (introduced in 1998) and to date the US is not one of them. Maybe so, but part of the military's decision not to use non-eye-safe lasers in battlefield conditions probably involves protecting our own soldiers. As I understand it, none of our own military personnel are allowed outside or anywhere they might be exposed to the beam when using the YAG laser range finder. "AN/PVS-6, MINI EYESAFE LASER INFRARED" http://www.globalsecurity.org/milita...d/an-pvs-6.htm BTW, as it happens, Sam's Laser FAQ includes a description of the unit I was building. I don't recall ever seeing the final assembly, but I sure recognize the oscillator sub-assembly. "Photos of Varo Rangefinder Erbium Laser" http://repairfaq.ece.drexel.edu/sam/...c/varopics.htm Please refer to the following photo: http://repairfaq.ece.drexel.edu/sam/...ic/varo-lh.jpg Notice the gold-colored section in the foreground with wires leading out of both ends. My job was to assemble at least ten (10) of those every day. I built them up on a base block, using a special jig that appeared to be manufactured out of monel. It consists of two eliptical, gold-plated reflectors; the Cr:Er:Glass rod (bottom of the elipse, and about the dimensions of an ink pen refill cartridge); the flashlamp (top of the elipse, about the size of a pencil); two metal support arms; two sets of rubber grommets for sealing the rod and flashlamp into the assembly via the metal support arms. I had to inspect under a microscope each laser rod that I used. First, I had to ensure that the ends of the rod had no more than an acceptable number of inclusions (bright stars in the field of view of the microscope) and scratches. Then, I had to use several types of solvents and some lens tissue to clean the ends of the rod. I had to use the microscope to ensure that my cleaning had been satisfactory. I placed the rod in a V-shaped holder in the jig. The assembly would be built up around it. The grommets were tough to put on the laser rod. They were made of rubber, which meant that they would contaminate the ends of the rod if they touched each other. It is difficult to slip a grommet over a tiny glass rod without allowing the grommet to touch the end of the rod. The grommets, themselves, had to be cleaned prior to use, too, and might be slippery from the solvents. I had to wear finger cots and use tweezers to handle the laser rod and grommets, and I had to change out my finger cots every 10 or 15 minutes to prevent my skin oils from contaminating the laser rod. Our materials suffered from various defects. The laser rods cost about $800, and most were coated by a third party. My employer tried to coat some of the rods, using our own optical shop up the hall. The results were horrible. Under the microscope some of the rods had just a few "stars." I understood those were coated by the third party. Other rods looked like a sea of stars. I understood those were rejected rods that our optical department had tried to salvage. The flashlamps cost about $50. Our electronics shop brazed the electrodes, but the results were often a brittle connection. If an electrode broke off during assembly of the laser cavity, the cavity had to be dis-assembled and rebuilt with a new flashlamp. This counted against the 10 units that I had to assemble each day. I found it expediant to bend the wires of the flashlamps "gently" when I took them out of the supply bin, so I could eliminate the brittle connections before I began assembly. My supervisor eventually noticed that I was rejecting a lot of flashlamps, and told me not to test them so aggressively. Of course, those wires could snap later during testing, but that would not be my immediate problem. And, as long as our units made it to out troops, breakage was not our problem at all. However, very few of our units actually shipped. Most failed in environmental testing. After I finished building each laser cavity on its block, I placed the unit on a cart. The next team took these units into a dark room, where the optics were tested and aligned. Somewhere along that time, the units were taken off the block I had used and were mounted on the plate that you see in the photograph. I remember seeing the rotating mirror (the Q-switch) and the circuit board, but that was a few yards farther down the room from my workstation, so I did not see it very often. Most of the time, I had my head stuck in the flowhood, "putting little screws into little holes," as I like to put it. |
#3
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That's a wonderful description of your assembly and QA procedures.
![]() Thanks, Sam. I'm sure this will find its way into my online diary, one of these days (it's only been 10 years since I worked there!). There is more I could add to it, but that's more along the lines of what life was like at that time and place than technical description. Erm... maybe I should add something about the QA Department? I don't have a lot of technical details I could add, but the gossip would be fine. Could be immortalized in the Laser FAQ. : It gives me great satisfaction that I can Google my name in your FAQ. Thank you for quoting me in the past, and I look forward to being of service to you in the future. |
#4
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#5
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For the record, I enjoyed it a lot also
Thank you, AES. (though I've been having to follow it as an OT discussion in r.a.p. since the Stanford Univ news server doesn't get alt.lasers -- want to try sci.optics, who might like it also?) I haven't figure out how to get this new Google interface to cross-post. |
#6
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There is more I should say about the gold reflectors that make up the
walls of the oscillating cavity. I don't remember just now (though I may have recorded it in my private diary) what the base metal is that makes up the reflectors. The coating is gold. The reflectors came to us the way all the other parts did, that is, in a bucket that was placed on a shelf of left on a cart. The reflectors were stacked on top of each other, with lens paper separating each reflector half, and each half was identitical by design. Their smooth, shiny, clean surfaces were beautiful. I had more of a chance to admire their beauty as I had to clean each reflector with solvents prior to assembly. A third party originally gold-plated the reflectors, but my company shifted to coating them in-house. I was impressed with the coating quality, considering the trouble we had with the laser rods. But, I did not have to examine the reflectos under a microscope for imperfections. Even so, there were still issues with the coating. There are tabs on the ends of the reflectors, which are supposed to fit into slots set within the end pieces. Metal, mostly the gold-plating, tended to build up on the tabs. Sometimes, the coatings were too thick to allow the two halves to fit together inside the slot. In that case, we had to file a little bit of the coating from the tabs. We had to be careful not to file down to the deepest base level (I believe there were three layers of metal making up the reflectors) or scratch the inside surface of the reflectors. Fortunately, it was not difficult to file down the reflectors according to specification, and I don't recall any reflectors rejected due to filing. I used a lens tissue to wipe up the filings from my workbench. I thought the gold in them might eventually become a significant amount, but it never did, as my supervisors had predicted. |
#7
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" Spewed...and was shut down.
If your assembly skills are as good as your grammar skills, our poor troops are screwed. Here's a hint, I won't even charge a fee for. But yourself a Thesaurus. BTW, I call B.S. on your story. I know our Government farms out to the lowest bidder. But damn, your a full blown tard. Surely they would not allow you to build field gear...surely... |
#8
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wrote in message news:
BTW, I call B.S. on your story. I know our Government farms out to the lowest bidder. BWAHAHAHAHAHA!!! moo |
#9
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![]() wrote in message ups.com... " Spewed...and was shut down. If your assembly skills are as good as your grammar skills, our poor troops are screwed. Here's a hint, I won't even charge a fee for. But yourself a Thesaurus. But yourself a Thesaurus? But yourself a proofreader! |
#10
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I have one, but your mom couldn't see the screen very well with her
mouth full and all... |
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