So excited to learn about different UV detection systems! Given how important it can be to block out UV, It's a great question to ask. Cheers for the great content as always!
Apparently with self-tinting (photochromic) glasses the process is reversed by (ambient) temperature, maybe it just was the heat introduced by the lasers, that caused the cards to reverse?
Another great video! I found that heat will reset many photo-reactive things. 2 of my videos to watch are " Photochromic Pigmented Color Changing Plastic " and " Phosphorescent Phenomena Experiments with Different Wavelengths and Temperatures ". Both are great additions to this video. You're also welcome to any raw footage I have for the follow up on this video if you want!
Most photochromic pigments can be reset by heat, but the ring-opening reaction in DTEs is thermally "forbidden", i.e. the probability is extremely low. So in theory, if you cook it in darkness, the molecule would decompose before it loses its color 💜
As far as CCFLs, the reptile bulbs are I believe no different from any other CCFL. One of the two or three major reptile supply companies published their so-called UV lights' spectra, it didn't even agree with their "UVB" marketing. Could you check into this?
I am especially interested in detecting UVB. I live in Germany and half of the year we can't produce Vitamin D in our skin because sunlight has a steep angle in winter so that no UV-B is coming to the ground, even in full sun. It's recommended to go outside in the summer without sunscreen but only for 20 minutes max to get the right amount of Vitamin D, but when is the time? And also, my birds can see UV light and need this special terrarium lamp, but I can't tell if the UV-lamp is worn off (what they do, they are bright, but not emitting UV light anymore after a while) Writing "UV-filter" on a plastic lid is somewhat like writing "no fat" on a package of gummi bears. 😀Because most of the clear material we use (glass, plastics) are not letting UV through. Even normal window glass is only letting a bit of UVA through. Thats why technical stuff which uses UV light (spectrometers etc.) is so expensive, they need quarz glass as material.
I test my glasses with paper money, Most currencies have some anti forgery marks that only show up when a UV light is shined on them, so put the lenses between the light and the note to see if it stops the mark showing up, Ive always been curious how effective this test is.
I have the same big UV detection card, the Chinese text under it said: "Put the detection area under sunlight, (and) determine the UV intensity by colour intensity"
I do have some magnesium strips somewhere in my storage. Could be interesting to test if they truly burn hot enough to emit UVC. Thanks for the suggestion and early watch! Hilsen tilbage fra Danmark ;)
some translation of the card: 微弱、较弱紫外线不至于伤害人体，无需防护=mild or weak UV does not do a significant harm to human body and there's no need to wear protections. 中等以上紫外线会伤害皮肤、眼睛，必须防护=UV beyond medium level will do harm to skin and eyes so the protections are necessary. 微弱=mild 较弱=weak 中等=medium 较强=strong 极强=ultra strong 将此感应区域置于阳光下通过颜色变化判断紫外线强度=Put the sensing area under sunlight and read the intensity of UV by color change.
I'd like to see a test of how long they would retain a message when they are kept in the dark. (e.g, a test of how transparent things are - nothing truely blocks ALL light)
I wonder if heating them up with a hair dryer would cause them to reset quicker! Maybe it has something to do with the heat the lasers can generate on the card?
I got fancy blue light glasses (purple/blue reflection). And I got a 365nm flashlight. When I shine my UV in the snow or wherever it is reflection, I do not see the UV light. So I easily can see fibers in the snow! I purchased cheap glasses with the coating from aliexpress, the plastic lens was different than my prescription. But the coating worked and kids could use the glasses.
Do they work with outdoor sunlight? I want to test if my sunglasses filter out UV from sun. Card should show strong color when exposed to outdoor daylight and no color if covered by sunglasses.
They sell cards for around $20 that apparently can detect xrays with a color change. Always been interested in buying one of those but if I bought everything that looked interesting to me I wouldn't have any room left in my house for me haha. I could always set up a tent in the backyard though....
Can you test uvc toothbrush holder oclean, philips etc, oclean version is open one not closed. Or maybe if you use larger philips uv cleaner, does it matter if comes little bit to the other room under the door.
I loved the video! Thanks for introducing me to this class of photochtomic dyes! In order to reset the card with light, the dye must absorb that specific wavelength so it's no surprise that a purple dye (absorbs green light) will be reset by a green laser. However, I would expect that the dye might also relax with a thermal mechanism. Did the thing get hot when irradiated with the IR lasers? Have you tried maybe warming the card with a hairdryer?
But I don’t understand the neon tubes that are found for example in discotheque (black light) or even in some doctors who use a Wood lamp dangerous for the skin?
Maybe temperature could also affect the reversing of the indicator pigment.... I hope you re-visit this, I would love to see those other wavelengths you mentioned, and maybe you could use some dry ice to reverse it - this way you wont get the paper wet (I THINK they're made from paper)
Glad you found it interesting :) A bit of a conundrum when UVB is beneficial to skin. But for most, some sunlight is a good thing. Too much is not.. Good luck with the treatment.
Do you have a speedlite style camera flash you could try to reset these with? Just point-blank with the test button. I doubt they're as powerful as the lasers but being such a wide spectrum might help.
cool, kinda similar to how OSL (optically stimulated luminescence) dosimeters work, they get "charged" with ionizing radiation, and when hit with light (usually laser) of one color, they emit light of other color, proportional to the dose of ionizing radiation they got charged with, but the mechanism is quite different, ionizing radiation creates electron-hole pairs that get trapped in special trap levels between the valence and conduction zones from which they can't escape because the gap they'd have to jump is much higher than room temperature energy, and when being measured, the stimulating light excites the electrons and holes into the conduction and valence zones from where they fall into recombination levels while emitting higher energy light
An interesting video. I feel bad about the big purple card, though. Still, it's good to know that it's not just infrared that's getting detected by various cards! I was excited about the middle one during the mass testing that occured as it did look quite interesting, but I'm sad to seee only the top-right part flouresce. Once again, I can't wait for your next video!
Writing and erasing with light the main technical aspect of re-writable CD-RW and DVD-RW and Blu-ray-RW disks / the optical drive can impart energy on a phase change material, thank you Stanford and Irish Ovshinsky who invented such technology :)
An interesting video (as usual) as i spent some time testing different UV filters whilst photographing fluorescent minerals and noticed that the UV light affected the camera sensor, i tested a number of camera UV filters, but the best filter was a pair of UVEX goggles hung in front of the camera lens. Also, I had some of that UV sensing Material in a chemistry kit from my Son, you were able to make UV sensing slime out of it.
For some reason my phone keeps playing UA-cam videos for seconds after leaving the app, so when I tapped on this video and left to save it in my history to watch later, I just hear a "HI"-
It's always fun when the UVC letters glow, I actually have a UV-C florcensent bulb and it glows UVC, Amazing. Edit: I’ve lost those small UV/UV-C cards, except I got them again, And they now sit on my dresser, Amazing.
It would be interesting to get links to the cards you used, so many various sources of these things out there it's not out of the realm of possibilities to get something that looks very similar but is just fake.
After watching the mishap with the laser zoomed in, heat does seem to be able to reset the card (notice the white central lines). But for some laser colors, the resetting happens so fast even with a wide, unfocused beam that it must be more than a thermal effect. Thanks for the early watch!
If the pigment is really DTE, the ring opening reaction is "thermally forbidden", but "photochemically allowed". Of course, it would be great to see a well-designed test of the theory 🤓
Thinking of UV in binary (ie. is and is not), especially the categorisation of UV, is the wrong mindset. The UV categories are as much a colour as they are in visible light, and so they need to be thought of in terms of colour shades. And when we think of UV in terms of bodily harm, bright (but visible) near-UV is probably still harmful, so I wouldn't fault the card for reacting to it.
As with the molecules in the cards, there are quite sharp thresholds for some of the molecules in our body, too. To our eyes, I think you are right, blue or violet light is harmful. But you can't get your body to produce Vitamin D with blue or UV-A light. It has to be UV-B, even if it is harmful at the same time.
The accidental card burn was honestly such a genius reminder that strong lasers are dangerous, _especially_ when you least expect them to be
So excited to learn about different UV detection systems! Given how important it can be to block out UV, It's a great question to ask. Cheers for the great content as always!
Glad you like the subject. The cards sure are a cheap alternative to buying a spectrometer ;) And thanks for the early watch!
I love the way you say hi, it feels really genuine like you are excited to be here. Makes the whole video more engaging! Love your content!
Apparently with self-tinting (photochromic) glasses the process is reversed by (ambient) temperature, maybe it just was the heat introduced by the lasers, that caused the cards to reverse?
it is exactly that. The higher the temp, the quicker the reset (within limits), as it is a structural change.
That's true for photochromic glasses, but not for DTEs, which stay colored for months in the dark, yet can be reset by light within seconds.
Another great video! I found that heat will reset many photo-reactive things. 2 of my videos to watch are " Photochromic Pigmented Color Changing Plastic " and "
Phosphorescent Phenomena Experiments with Different Wavelengths and Temperatures ". Both are great additions to this video. You're also welcome to any raw footage I have for the follow up on this video if you want!
Most photochromic pigments can be reset by heat, but the ring-opening reaction in DTEs is thermally "forbidden", i.e. the probability is extremely low. So in theory, if you cook it in darkness, the molecule would decompose before it loses its color 💜
Clive tested the same small rectangular card and got the same results. I agree with you it'd be nice to have a card like the bigger one for UVC.
As far as CCFLs, the reptile bulbs are I believe no different from any other CCFL. One of the two or three major reptile supply companies published their so-called UV lights' spectra, it didn't even agree with their "UVB" marketing.
Could you check into this?
Thats a CFL, not a CCFL. A CFL has a heated cathode, a CCFL is a cold cathode lamp.
That was great! I hope you will keep making videos like these in the future.
Glad you liked it. Much more videos to come :)
This is such a cool channel
You're an unbelievably underrated creator, this kind of thing deserves to be on TV
Every video that you make, i'm always interested to watch! 😊
I am especially interested in detecting UVB. I live in Germany and half of the year we can't produce Vitamin D in our skin because sunlight has a steep angle in winter so that no UV-B is coming to the ground, even in full sun. It's recommended to go outside in the summer without sunscreen but only for 20 minutes max to get the right amount of Vitamin D, but when is the time? And also, my birds can see UV light and need this special terrarium lamp, but I can't tell if the UV-lamp is worn off (what they do, they are bright, but not emitting UV light anymore after a while)
Writing "UV-filter" on a plastic lid is somewhat like writing "no fat" on a package of gummi bears. 😀Because most of the clear material we use (glass, plastics) are not letting UV through. Even normal window glass is only letting a bit of UVA through. Thats why technical stuff which uses UV light (spectrometers etc.) is so expensive, they need quarz glass as material.
In America, we just drink Vitamin D milk, so this isn't an issue.
I test my glasses with paper money, Most currencies have some anti forgery marks that only show up when a UV light is shined on them, so put the lenses between the light and the note to see if it stops the mark showing up, Ive always been curious how effective this test is.
I have the same big UV detection card, the Chinese text under it said: "Put the detection area under sunlight, (and) determine the UV intensity by colour intensity"
Gotta love the way you say oh boy when you had to say a word. XD
All of these detection methods are new to me. Thank you.
I was going to say we live in a fascinating world. but this sort of thing might be happening elsewhere too. Fascinating !
Do you think you can test using flash power for uvc? Or just burning magnesium even? Hilsen fra Island! :)
I do have some magnesium strips somewhere in my storage. Could be interesting to test if they truly burn hot enough to emit UVC. Thanks for the suggestion and early watch! Hilsen tilbage fra Danmark ;)
some translation of the card:
微弱、较弱紫外线不至于伤害人体，无需防护=mild or weak UV does not do a significant harm to human body and there's no need to wear protections.
中等以上紫外线会伤害皮肤、眼睛，必须防护=UV beyond medium level will do harm to skin and eyes so the protections are necessary.
微弱=mild
较弱=weak
中等=medium
较强=strong
极强=ultra strong
将此感应区域置于阳光下通过颜色变化判断紫外线强度=Put the sensing area under sunlight and read the intensity of UV by color change.
I love this guys intro concept
This card could be used for UV photography.
Same, I’m getting the same card, (the one that says UV and UVC.)
I'd like to see a test of how long they would retain a message when they are kept in the dark.
(e.g, a test of how transparent things are - nothing truely blocks ALL light)
DTEs can stay in their closed form for months, but a test of the cards would be cool to see.
There are many things that block all light, i hope you know that.
At 8:16 the IR laser some fast decaying dark trace on the right side card, I wonder if it was real effect or just a camera artifact.
I wonder if heating them up with a hair dryer would cause them to reset quicker! Maybe it has something to do with the heat the lasers can generate on the card?
I would not think heat has anything to do with different wavelenthgs of light. But it should be simple enough to test of course.
If they really contain DTEs, then heat shouldn't matter. But a phone white light on full power will reset them within seconds.
I was really bored today, thank you for saving me. I get very bored when I am not having school!
I got fancy blue light glasses (purple/blue reflection). And I got a 365nm flashlight.
When I shine my UV in the snow or wherever it is reflection, I do not see the UV light. So I easily can see fibers in the snow! I purchased cheap glasses with the coating from aliexpress, the plastic lens was different than my prescription. But the coating worked and kids could use the glasses.
That is the coolest watch I have ever seen!
"UV Protection Brainiac can't hurt you"
UV Protection Braniac: 6:26
Hey! Thank you for making this vid!
Hi Martine. Glad you liked it - as always ;) And thanks for the early watch.
Please provide a link to buy both UV/UVC cards and the infrared detection card as well.
Do they work with outdoor sunlight? I want to test if my sunglasses filter out UV from sun. Card should show strong color when exposed to outdoor daylight and no color if covered by sunglasses.
Thanks you.
You've answered all my questions with this video.
They sell cards for around $20 that apparently can detect xrays with a color change. Always been interested in buying one of those but if I bought everything that looked interesting to me I wouldn't have any room left in my house for me haha. I could always set up a tent in the backyard though....
How does temperature affect the different cards?
Can you test uvc toothbrush holder oclean, philips etc, oclean version is open one not closed. Or maybe if you use larger philips uv cleaner, does it matter if comes little bit to the other room under the door.
Do you have a part number for the 3watt UV light source and does it require a ballast or dropping resistor to operate on 230 Vac?
i wonder if you could reset it faster using temperature. like warmer/colder
Probably not, but should be tested. Phone light on full power resets DTEs within seconds.
I loved the video! Thanks for introducing me to this class of photochtomic dyes!
In order to reset the card with light, the dye must absorb that specific wavelength so it's no surprise that a purple dye (absorbs green light) will be reset by a green laser.
However, I would expect that the dye might also relax with a thermal mechanism. Did the thing get hot when irradiated with the IR lasers?
Have you tried maybe warming the card with a hairdryer?
Wonderful job as always. Quite interesting what wavelengths of light can be used to reset the UV detector.
But I don’t understand the neon tubes that are found for example in discotheque (black light) or even in some doctors who use a Wood lamp dangerous for the skin?
Maybe temperature could also affect the reversing of the indicator pigment....
I hope you re-visit this, I would love to see those other wavelengths you mentioned, and maybe you could use some dry ice to reverse it - this way you wont get the paper wet (I THINK they're made from paper)
Really cool tests of this cards !
I have to use uvb lamp to treat my vitiligo so this was interesting to me.
Glad you found it interesting :) A bit of a conundrum when UVB is beneficial to skin. But for most, some sunlight is a good thing. Too much is not.. Good luck with the treatment.
I love the August is Falling logo after you burn through the card on accident
I bet this vids gonna be a great one 😁😁
I sure hope so ;) Thanks for the early watch!
@@brainiac75 😁 it was cool!!
Great video, i love watching stuff like this.
How do the other cards react to the visible violet light?
Do you have a speedlite style camera flash you could try to reset these with? Just point-blank with the test button. I doubt they're as powerful as the lasers but being such a wide spectrum might help.
cool, kinda similar to how OSL (optically stimulated luminescence) dosimeters work, they get "charged" with ionizing radiation, and when hit with light (usually laser) of one color, they emit light of other color, proportional to the dose of ionizing radiation they got charged with, but the mechanism is quite different, ionizing radiation creates electron-hole pairs that get trapped in special trap levels between the valence and conduction zones from which they can't escape because the gap they'd have to jump is much higher than room temperature energy, and when being measured, the stimulating light excites the electrons and holes into the conduction and valence zones from where they fall into recombination levels while emitting higher energy light
An interesting video. I feel bad about the big purple card, though. Still, it's good to know that it's not just infrared that's getting detected by various cards!
I was excited about the middle one during the mass testing that occured as it did look quite interesting, but I'm sad to seee only the top-right part flouresce.
Once again, I can't wait for your next video!
Writing and erasing with light the main technical aspect of re-writable CD-RW and DVD-RW and Blu-ray-RW disks / the optical drive can impart energy on a phase change material, thank you Stanford and Irish Ovshinsky who invented such technology :)
can those card be repeatedly used? and like how many times before they loose their effectiveness
I would think a Flat Bed scanners Bright white light would work well to reset it.
hi! your videos are great!
nice vid! where did you buy the test cards?
An interesting video (as usual) as i spent some time testing different UV filters whilst photographing fluorescent minerals and noticed that the UV light affected the camera sensor, i tested a number of camera UV filters, but the best filter was a pair of UVEX goggles hung in front of the camera lens. Also, I had some of that UV sensing Material in a chemistry kit from my Son, you were able to make UV sensing slime out of it.
Great video so far!
7:17 I didn't hear correctly the bit before and I switched off because I thought that was the end
For some reason my phone keeps playing UA-cam videos for seconds after leaving the app, so when I tapped on this video and left to save it in my history to watch later, I just hear a "HI"-
This reminds me of the glasses that darken when you shine a light on it
Great video, thanks for making it.
Ooh, what about the beads? Can they be reset too?
It's always fun when the UVC letters glow, I actually have a UV-C florcensent bulb and it glows UVC, Amazing.
Edit: I’ve lost those small UV/UV-C cards, except I got them again, And they now sit on my dresser, Amazing.
You can get just two cards and put one aside to reset... But your idea using lasers is still cooler :D
A phone light on full power should be able to reset the card in seconds.
It would be interesting to get links to the cards you used, so many various sources of these things out there it's not out of the realm of possibilities to get something that looks very similar but is just fake.
where can I buy a UV flashlight like that? One that actually does what it says not some fake crap?
1:43 if anyones curious on the exact pronunciation it would by di-thienyl-ethenes
UVC emits a very beautiful teal color. Sucks that its dangerous in only moderate quantity. Wish I could replicate the color with an RGB bulb.
3:04 what type of pleco do you own?
Where can these cards be purchased?
how about a highpower green led as a resetting device?
0:23 what the hell is that noise
I love your humor.
Thanks! Great video 👍
Your uv light power ?
365 or 395
Isn't the resetting a thermal effect?
After watching the mishap with the laser zoomed in, heat does seem to be able to reset the card (notice the white central lines). But for some laser colors, the resetting happens so fast even with a wide, unfocused beam that it must be more than a thermal effect. Thanks for the early watch!
@@brainiac75 Just saying, because more heat also speeds up the light release from luminescent materials.
If the pigment is really DTE, the ring opening reaction is "thermally forbidden", but "photochemically allowed". Of course, it would be great to see a well-designed test of the theory 🤓
4:01 Now THAT was a Blooper!
I didn't see the round blue one in the middle react to anything....cheers.
Seus vídeos são muito bom, sucesso!
What about cold water?
Very Interesting Video! :-)
Laser light show + UV detection card = laser E-ink display?
I use a little uv flashlight and my goverment id cards uv security feature to test sunglasses uv protection
Fascinating!
6:26 Show up at a bank like that and you are in for a new Pay Day 2 mission. 😂
Watching laser videos without safety glasses always feels wrong. 😅
That's funny , Imagine if all products only showed the molecular arrangement diagram with no words in the ingredients . LOL!
its better to think good safety equipment is bad than to think bad safety is good
how about led bulb 💡
use hairdryer to reset the cards with heat
06:27 lmao its almost an EVA suit for a space walk.
"Strong amber searchlight." Sun?
Thinking of UV in binary (ie. is and is not), especially the categorisation of UV, is the wrong mindset.
The UV categories are as much a colour as they are in visible light, and so they need to be thought of in terms of colour shades.
And when we think of UV in terms of bodily harm, bright (but visible) near-UV is probably still harmful, so I wouldn't fault the card for reacting to it.
As with the molecules in the cards, there are quite sharp thresholds for some of the molecules in our body, too. To our eyes, I think you are right, blue or violet light is harmful. But you can't get your body to produce Vitamin D with blue or UV-A light. It has to be UV-B, even if it is harmful at the same time.
That keychain indicator, while pretty looking, seems too inaccurate for any useful purpose. Neat idea though
Don't believe this card. Even uvb like 310nm also shows green UVC letter.
Great 🔥 🔥
I think the heat will recover the cards
Bro's outro sounds like he's threatening to kidnap ma dog's gf
4th?
An early watch indeed, thank you :D
@@brainiac75 teehee
Make a video: generate 7k gauss over 1 inch space between magnets
Got here first minute
Thanks for the early watch :D