Using blue rays in scanners?

[-bart-]

Why is no one referring to the MPE-tables? Lots of research has been put in putting these together. It is the perfect guideline for safe scanning. Surely all laserists do make MPE calculations at some point, don't they?

In these tables 405nm is considered as visible light, and must be treated as such.
On the other hand, if you want to be on the safe side you can consider it as <400nm
You might want to exclude the eye-reflex time of 0,25 seconds because of its poor visibility.

http://www.physics.leidenuniv.nl/edu...MPE-tables.pdf

[Things]

Not sure why people would want to crowd scan with deep UV

I guess you could just use an IR laser and give everybody IR detecting night vision goggles, cheap whitelight

[keeperx]

Not sure why people would want to crowd scan with deep UV

I guess you could just use an IR laser and give everybody IR detecting night vision goggles, cheap whitelight

well im in the US so i cant, but I can see why.... florescence comes to mind...

[mixedgas]

health issues are just steve being paraniod...
the UV in a BR diode is no worse than black light, the sun, tanning.. nobody is saying that its great for your skin, but neither is masturbation and we all still do that....

YOU sir are pissing me off, I've been at this since 1987, and you dont even have scanners up yet.
Don't make statements you cant back up. When you have attended university and ILDA laser safety classes, you can talk.

Steve

[keeperx]

if a show takes into account the proper MPE for visible light, then there is no difference in the safety of show thats using 405 or 445 or 473. the MPE tables are one guide and safe scanning practices are another.

You keep saying that for some reason 405 should not be considered as normal visible light. but if you are scanning a safe show, it really makes not difference. 405 is Near UV.. now there is some debate as to weather light can ve UV and visible at the same time (i say why not) but that does not change the fact that the MPE tables include 400-700 as visible light.

nobody is saying bluray is SAFE. just that if the same precautions are taken with 405 as any other visible light, there should be no problem.

and i stand by my statement... i believe being scanned with a 405nm laser (while wearing the proper eye protection) is safer than a UV tanning bed


Now i may be missing something (that always seems to be the case) but based on my understanding 405 should be treated as visible light..

[mixedgas]

"if you are wearing proper eye protection" wrote keeperx

Have you ever even looked at a MPE table, or are you just parroting what you have seen here?

If you are wearing eye protection you are not seeing enough light to use the blu-ray.

I own OD3 and OD6 goggles for a wide variety of wavelengths, I somehow doubt you have even put on a pair.


At OD3, its like wearing totally black dark sunglasses. At OD6, you wont see it at all. OD is a log function, OD1 or OD2 are a joke. OD3 starts to get serious.

How do you see the near UV if your wearing a adsorber?

I just got a copy of the more detailed tables from a former coworker, I will run the numbers for a close up wall scattering.

When you have personally experienced conjunctivitous from a UV source you can talk. I have.

The willingness to make statements "such as he's being paranoid" without running calculations is very unprofessional in attitude. That is why in the other thread I have basically said"I'm not sure yet, but a level of caution is in order". I AM NOT paranoid. I have a excellent record of lab safety working with stuff that would blow your mind. Including some that I can't even think about discussing for 25 years. And in my former job I was known for being a bit cavalier with safety, far less then paranoid! What my coworkers thought was cavalier was usually already designed to be self limiting in scope, and quite a few of them couldn't grasp that.

You have direct evidence from one fellow poster that he observed a instant change in skin color, what more do you want? I too have experienced "direct writing" of skin tone at selem from a 405 source. Oh and btw, 405 is a average, some of these could dip as low as 385 nm.

Don't ever just blow off a engineering safety warning.

Once upon a time I had about 3000 watt seconds of focused strobe set up on a experiment. A so called safety person from the university health and safety department showed up for a inspection. She barged right in through a warning door and exercised her legal right to kick me out of my own lab. I warned her and her student assistant that a high energy experiment was in progress and that she would require assistance to remain in the room. She flashed the ID badge that said she had the legal authority to kick me out . I warned her again about high voltage and high energy and retreated to a safe distance, failure to leave could could result in arrest. I stayed in a distant doorway and was on the phone to my boss to get her kicked out. Before I could get across the room to knock it out of her hand, she reached into her pocket and then aimed a small digital camera with a SLR optical viewfinder at my experiment with the safety curtain open. She hit the shutter and her camera did a exposure test flash. That armed the optical triggers on my slaved strobes. A few milliseconds later her camera did a red eye reduction flash. That triggered the pulse counter on the optical trigger and 3000 joules in 200 microseconds headed right down the viewfinder lens of the camera right onto her retinas. She's lucky the strobe was set to LOW power that day and that her viewfinder only sampled a fraction of it.

She yelped and looked like she was standing up brain dead for a about 30 seconds, like she was hit by a taser. She started crying and turned to her student assistant, sobbing, and said "Why did it do thatttttt ?"

Turned out she was not qualified to even look at electrical engineering safety, by the time I got done she wasn't even allowed on my floor. She's back to dorm safety where she belongs. BTW, I was cleared of all responsibility for her actions, as I warned her. She got nailed for exposing her assistant to the flash and disregarding the warnings. She opened the cabinet to take a picture through the rear safety housing of what she thought would be a fire hazard. If she would have asked, she would have been told it was a fireproof drape.

No permanent damage, she's damn lucky. But when I post a warning, I mean it!!!!!!!!!!!!!!!!!!

[keeperx]

well i assume your talking about photokeratoconjunctivitis caused by UVA rays, but im still wondering why if 405 is UVA, its not classified as UVA, or is that just because it is also visible?


-------------------edit------------------------

BTW its great for MRSA..
http://www3.interscience.wiley.com/j...53714/abstract

[QUAZAR]

Nice story Steve. I really get bugged by "know it all do gooders".
As a slight diversion from lasers, I am also aware of the dangers of UV from using discharge lamps in modern intelligent light fittings. I have had to do repairs and maintenance to lights with the covers off and bulbs lit. Although I havnts had a direct hit from light being output through the lens systems, just the intense glow from a HID is enough to give headaches.

[colouredmirrorball]

I've heard of that HID's... they seem very powerful and dangerous to me. It hurts my eyes slightly to look in the 100 W lamp in my scanner, so I can imagine how bright those lamps are.

[mixedgas]

streetlight and commercial lighting HIDs (at least by law in the uS) have two atmospheres of nitrogen in the outer jacket and special adsorbing outer glass to get most of the UVB and UVC they emit. They do leak small amounts of UVA, and the ones with no outer jacket, just a quartz envelope, leak UV like there is no tomarrow.

I love em, I made a ton of money off them, and really think they are a better source then leds for area lighting in the immediate future.

I love how I could order different color temperatures, you could get a nice warm white.

But yeah, instant headache, especially the 400 watt and 1000 watt ones.

Steve