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Detecting Potential Reflection Hazards

Mathewe

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My boss just purchased a 'Hand-Held' laser 'WELDING' system ( bad idea, IMHO... via the education/quality of the typical class of help that he hires). The manufacture's instructions loosely state SERIOUS cautions/warnings concerning safety, but don't properly disclose anything but 'minimum' protective measures. In such, my boss is cutting LOTS of corners in setting this dangerous thing up. He doesn't get it! He does not realize how dangerous reflected laser light can be to those, in close proximity to its operation! He kinda "Poo-poos" my warnings and suggestions. In short... how can I prove to him, before everyone goes blind, that he needs to spend the money and take the time to actually do this 'CORRECTLY'? Are there any IR laser detectors out there that will show just how much reflected laser light is actually being reflected and tossed around the shop? Would our cell phone camera's detect dangerous reflections? Maybe someone has a simple circuit design, that I can build, in order to test the true safety of the area surrounding the operation of this laser and the lacking safety of its rather 'BAD' work station design...???
 



farbe2

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You could use a cheap webcam or an old Phone.
New phones have IR filters in front of there cams, so not usable.
You can check the camera in question by looking at a TV remote and pressing a button. If you can see the light the remote emits, it should be usable.

However it depends on the wavelength of the laser, if its to "high" infrared, no cam will detect it.
There are also these IR indicator cards that are used for aligning IR lasers. These are plastic and have a IR light sensitive coating that changes color if IR hits it. Look at thorlabs for getting one.
 

bostjan

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A Raspberry Pi IR Camera *should* work, and they are quite inexpensive... but, without knowing the wavelength of the welder, no one can guarantee anything. I'm guessing it's around 1 µm, but guessing isn't going to protect your retinas!
 

Mathewe

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I contacted Thor Labs about this. I was told that the 900nm-1200nm wave-length was probably not going to show up via digital camera capabilities. I'm going to try one of their NIR detection cards, tuned for 700nm-1500nm. There's no guarantee that it will effectively work in detecting dangerous, reflected collimated light... but it's my only hope at this time. There's no way the owner will pay for a proper NIR/IR viewer just for a one shot test. The owner just needs to 'pony-up' extra $$$, totally close up the work station, put a roof on it... and do things properly!!!!!!!!!!!!!!
 

steve001

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I contacted Thor Labs about this. I was told that the 900nm-1200nm wave-length was probably not going to show up via digital camera capabilities. I'm going to try one of their NIR detection cards, tuned for 700nm-1500nm. There's no guarantee that it will effectively work in detecting dangerous, reflected collimated light... but it's my only hope at this time. There's no way the owner will pay for a proper NIR/IR viewer just for a one shot test. The owner just needs to 'pony-up' extra $$$, totally close up the work station, put a roof on it... and do things properly!!!!!!!!!!!!!!
What country do you reside in?
 

Mathewe

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OSHA might have something to say about it
Why did I feel that this was 'exactly' where you were wanting to go when you first asked me what country I resided in?
I'm not looking to punish my employer. I'm wanting to educate!!!
 

steve001

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Why did I feel that this was 'exactly' where you were wanting to go when you first asked me what country I resided in?
I'm not looking to punish my employer. I'm wanting to educate!!!


What better way to educate than point this employer to this site so he can read for himself the consequences of an unsafe workplace? If he will not take sound advice than let him suffer the outcomes should they happen
As for you put your concerns on the back burner as you've done all you can
 
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bostjan

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I contacted Thor Labs about this. I was told that the 900nm-1200nm wave-length was probably not going to show up via digital camera capabilities. I'm going to try one of their NIR detection cards, tuned for 700nm-1500nm. There's no guarantee that it will effectively work in detecting dangerous, reflected collimated light... but it's my only hope at this time. There's no way the owner will pay for a proper NIR/IR viewer just for a one shot test. The owner just needs to 'pony-up' extra $$$, totally close up the work station, put a roof on it... and do things properly!!!!!!!!!!!!!!

1. First and foremost, without knowing the wavelength that the welder is outputting, there are absolutely no guarantees. I'd say that the most important thing would be to look up the make and model of the welder and ascertain the output wavelength.

2. Thorlabs' response seems to be valid for a standard webcam, not the NIR cameras. At any rate, though, it does seem like the sensitivity of those does drop significantly starting around 1 µm (1000 nm), so, by 1200 nm, it might not be possible to get a good gauge of how much light is leaking. There are wider-band deep IR sensors as well, but again, you need to know the output wavelength in order to sense the output.
 

Mathewe

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1. First and foremost, without knowing the wavelength that the welder is outputting, there are absolutely no guarantees. I'd say that the most important thing would be to look up the make and model of the welder and ascertain the output wavelength.

2. Thorlabs' response seems to be valid for a standard webcam, not the NIR cameras. At any rate, though, it does seem like the sensitivity of those does drop significantly starting around 1 µm (1000 nm), so, by 1200 nm, it might not be possible to get a good gauge of how much light is leaking. There are wider-band deep IR sensors as well, but again, you need to know the output wavelength in order to sense the output.
The welder's output is stated to be between 900nm and 1200nm. I'm not sure why it's output is stated that way. Shouldn't something like this have a 'steady' output regardless of how much power is being used (thin metal power vs. higher power for thicker metals)? I don't get it. Shouldn't my 445nm blue laser 'ALWAYS' be 445nm at 'any' power setting? Why would this NIR wavelength laser be any different?
 

Mathewe

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What better way to educate than point this employer to this site so he can read for himself the consequences of an unsafe workplace? If he will not take sound advice than let him suffer the outcomes should they happen
As for you put your concerns on the back burner as you've done all you can
I get what you are saying. I think that the main problem is that he found a good sales-person who saw him coming. It's hard for me to put my concerns on the back burner, but I really have no choice at this point. I truly 'have' done all that I can do! After voicing all of my concerns, numerous times, he finally pulled me to the side, today, and diplomatically asked me to shut the hell up. The person that he bought that gadget from has 'assured' him that all is fine... and that's good enough for 'HIM'! I'm not buying it. I pulled a tall cabinet in front of my computer station, today. I won't catch any stray NIR reflections coming from that laser station. My fingers are crossed for everyone else in the shop...
 

bostjan

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The welder's output is stated to be between 900nm and 1200nm. I'm not sure why it's output is stated that way. Shouldn't something like this have a 'steady' output regardless of how much power is being used (thin metal power vs. higher power for thicker metals)? I don't get it. Shouldn't my 445nm blue laser 'ALWAYS' be 445nm at 'any' power setting? Why would this NIR wavelength laser be any different?
With any measurement, there is a tolerance, but 1050 ± 150 nm seems more like an umbrella statement covering multiple products than a measurement tolerance. Have you done a search on the product? What is the make and model?

Something like the Lightweld 1500 has a dominant output wavelength of 1070 nm. While a cheap no-IR-filter webcam will not be super-sensitive to that wavelength, it should still show up well enough to detect a light leak, but if the system you have is 1200 nm, probably not.

Hopefully the Thorlabs card will work well enough and you can move on.
 

smallfreak

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here's no guarantee that it will effectively work in detecting dangerous, reflected collimated light...
No, it will not. These cards are meant to directly show the collimated beam in a place where you expect it to be. They need quite high energy density to show the effect and you need the contrast of the surrounding area where the beam does NOT hit to see it.

Even IF it would be able to detect a beam gone astray, you would have first to locate the card there. This essentially means you would have to hold the card in every mm² of the entire room as you would not know in advance where to look for an invisible ray.

I too think that's quite a bad idea to operate such a powerful and invisible(!) laser outside a tight enclosure and proper auto-shut-off measures in case someone opens the lid. For handheld this "enclosure" would cover the entire room. I do think that there ARE some regulations how to set up the environment for such use, even in the US.

Well you can argue that the eye lens is bad in focusing NIR light so even a collimated ray will not produce the same tiny spot than a green one. And you may argue that there is hardly any chance to find a collimated ray going astray in a welding laser with a short focus length. But at the power needed for this kind of use even diffuse reflection, badly focused may reach enough energy density to permanently damage the eye.

The bad news is, that it's not only the chance of an instant flashing, but as well the cumulative degradation due to tiny, unnoticed injuries over time.

There really should be a requirement to mix a visible (low power) green laser into the beam of the IR working beam as some kind of leak indicator. You at least would be able to guess where the IR is heading without special equipment, even if the optics optimized for NIR does not handle the green light with equal precision.

Hmmm... Maybe I should file a patent claim for this. 🤔
 




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