Posted By John Lewis We use four Class 1 laser marking devices on our two sites. They are regularly maintained and checked and if problems arise they are repaired tout suite i) for safety and ii) to maintain production. Today, one of the operators has told me that a "mate of his who used to do TIG welding says the glass screen has to be changed every 6 months". I am always wary of conversations that begin "a mate says" and pretty much convinced this his statement is incorrect as I've never heard of it before. If the glass is in any way damaged or scratched then yes, but every six months? Please tell me I am right, I have looked in the manufacturers manual and all my laser safety stuff. There is mention in regard to Class 4 because of degradation of the coating, but this one has stuck a thought in my head. John

Posted By Alan Nicholls Type of equipment could also have a type 2M laser source. Try the hpa web site they will answer most questions and its just an email away. www.hpa.org.uk/radiation/faq/laser/index.htm The email address can be found in the faq section , Who should I contact if I have more questions. Hope this helps Regards Alan N

Posted By Merv Newman A class 1 laser' is "inherently safe" (don't believe all you read) and I doubt it could be used for marking as it is not very powerful. This sort of level is used to read CDs and to illuminate pop concerts. Class 4 will burn through stainless steel. (I could probably quote petawatts but shan't) "Marking" lasers will be class 2 or 3, depending on the materiel to be burnt. Totally enclosed area with no possibility of reflection into the eyes. No-one needs to see a 2, 3 or 4. Maybe the maintenance technician (highly trained and aware) will check the results of a burn, and will be wearing appropriate (for the wavelength) eye protection. What glass are we talking about anyway ? Merv

Posted By John Lewis Guys, thanks for your help so far. The additional information I should have put on the first post is that the machines are stationary units used for marking Stainless steel, Cobalt chrome and Titanium components in a factory environment. The manufacturers handbook states that it is a Class 1 device and there is a label on the outside of the machine stating that, but it is unclear if that is with or without the door shut (is a there a distinction?). The doors are fully interlocked and the machines will not operate with them open. Our own people do not do any maintenance involving the laser at all, that is left to the manufacturers man. As it is an area of the work which seems to be organised I have let it be for now as there were bigger fish to fry in the company. Now is probably a good time to look at it in more detail. John

Posted By John Lewis Thanks everyone for your input. I have put laser safety on my white board as an action point to be looked into. John