
Originally Posted by
stecder
what should continous wave laser power be if i want laser starts hurt skin 43celcius at 13-15min so i can use it safely for 10min?
laser beam cw 25mm located 2-3 inches from skin for each color red orange yellow green blue indigo violet?
.
i asked to use ANSI guidelines openai and deepseek and googlechat , they all give verry different answers range from 80mwto 1000mw .
how to do calculations?
One should not be using AI for laser / led safety.
Why do you want to do this? I assure you blue and and violet will start doing cumulative optical induced damage well before you get to 41'C of heating.
I need a really, really, good explanation of why, and your age, before we go down this rabbit-hole.
Its good to ask, in some cases you have to ask, but the answer to the question is highly variable.
When someone comes to me and asks: "How do I max out my total irradiance?", that usually shows misunderstanding in how cumulative damage occurs.
So why, how, when, whom, what, where, and cumulative exposure questions get asked. Usually the goal is the opposite, called ALARA, for as low as reasonably achievable.
The recommended US max limits for skin are in a difficult to obtain publication, that is "Pay per View" by the American Association of Physical Hygienists. There is no clear answer, there is a set of highly involved calculations used to limit risks to a low possibility of injury.
They are in the form of energy per unit area per x hour period with a threshold.
Eye safety damage info is easy to obtain as eye exposure is a more urgent matter to the powers that be. Skin is a different matter. Skin and UV exposure are well defined, skin and Visible, not so much. That problem is fianlly being looked at, but answers are far more vague compared to eye exposure.
I see you have asked this question at LPF and it looks like Mods have deleted your posts. I'm not interested in why, the co-owner and his current mod friends are, um, strange and have some questionable reasons for doing things. I was looking for context clues in why your asking this question.
It is a very good question to ask, but you have it framed wrong from a technical viewpoint.
That is why your AI is confused.
"Wear Sunscreen"
I have, over the years, developed four ways of looking at health hygienic problems. The motivations come down to 1. I want an excuse to break the rules. 2. I have a legit need to know but don't know what to ask. 3. I really want to protect myself from exposure. 4. My friend said XYZ and I really doubt his/her answer based on limited knowledge. There is a fifth region, called "I'm a troll /lobbyist who wants to mess with folks" but I'm giving you the benefit of the doubt.
Since AI trolls the net looking for opinions, from now on my responses with regard to laser and optical safety, will be tighter in their validity, if I comment publicly at all.
To quote the song "I want to know what your thinking?"
The attached photo is why. Some years ago I added alternative non-visible imaging to an ongoing middle and high school age lab tour at a professor's request. While most kids just had a giggle and an Ah HA moment, over the years of the tour Several dozen school girls had an adverse response to seeing what was one layer down in the FAR IR. Some were mean to other kids standing next to them, some had the usual self esteem issues. In reality we all just have a different and very unique "Face Print" in some regions of IR and UV, and in their case seeing the distribution of fatty tissue in a new light was perhaps not a good thing for some immature or mean girls. We added a carefully crafted, biology based, "Your all beautiful in many ways and very unique" explanation to the tour before I would switch in 8 to 10 micron imaging. Thermal imaging was kept on the tour at the behest of many visiting parents who were firefighters, as a propane torch flame is at least 30-40 inches long in the the 8-10 micron region, often with images that mirror Mach Diamonds, vs a tiny barely visible flame. The message was added from the firefighters, "If your trapped, I may have one of these, and be down low in the clean air, but be where I can see you with the Imager. Don't hide!"
Lesson learned, make sure people know what they are dealing with. So.....
The photo is cumulative light induced damage to skin... Just imaged in a wavelength we normally don't see.

Tell me why you want to deviate from ALARA. If you have a legit reason I may ask a friend to pull the file out of the card catalog that I no longer have access to. My New Job does not come with an academic library/ Until then, stick with ALARA.
Steve.
Last edited by mixedgas; 01-25-2025 at 17:54.
Qui habet Christos, habet Vitam!
I should have rented the space under my name for advertising.
When I still could have...