Replies

1. 
   BobS | Aug 09, 2005 05:01pm | #1

   RJT-

   I know a little about lasers from some research I did a few years ago which may or may not still be valid. But here goes...

   Laser safety is governed by the International Electrotechnical Commission (IEC) which has guidelines for how each laser is classified. This depends on the "on time" of the laser, wavelength, beam shape, power, etc. The IEC also provides a method for calculating the critical parameters which boils down to power/unit area/unit time.
   I should mention as an editorial - I've found these guidlines somewhat confusing and they look like the might be easily fudge-able. That said, all the tools I've seen lasers on, are "Class 1 Laser Products" which, if I recall correctly, means they are safe under reasonably forseeable conditions with no protective eye glasses. I wouldn't buy a product that was not Class 1 eye safe.

   That said I still don't look at the beam emitter and I'd advise others not to.

2. 
   Ricks503 | Aug 11, 2005 05:28pm | #2

   I think he was responding to another post and responded to yours with comments for the other

   1 - measure the board twice, 2 - cut it once, 3 - measure the space where it is supposed to go        4 - get a new board and go back to step 1
3. 
   WayneL5 | Aug 13, 2005 10:14pm | #3

   You can tell the potential for harm from the class of the laser.  There are four classes, I, II, III, and IV, with some subclasses.  The lower the class, the lower the risk.  Risk is based on whether there is enough power in the laser to damage the eye, or in stronger lasers, to burn skin or set things on fire.

   Class I lasers are so weak that staring at a spot they make on a surface or even looking directly into the beam for a reasonable time will not cause harm.

   Class II lasers can cause harm if you stare into the beam for more than ¼ second, but you can look at the spot without harm.

   Class III lasers can be harmful from fairly brief looks directly at the beam, depending on the subclass.

   Class IV lasers burn through things, set things on fire, and knock missiles out of the sky.

   Here are more detailed discussions of laser classes.  http://ehs.uky.edu/radiation/laser_fs.html  http://www.laserinstitute.org/publications/safety_bulletin/laser_safety_info/