Good UV versus bad UV. All available on eBay.

[@origamihawk]

I feel like big clive might actually save me from a lot of pain at some point in my life.

[@christophermaciulaitis7745]

Like the taste of Meths. Next, mineral Turpentine.

[@SakosTechSpot]

oragamihawk Clive has saved my life. He inspired me to get a multimeter. When I thought I turned off the switch for the room, I double checked with the meter. It was still on. Wouldn't have checked if I never watched his vids. Thanks Clive!

[@SakosTechSpot]

I turned off the switches from the circuit breaker which SHOULD have been for the room, turns out whoever installed or added it wired it to a different switch. Guessing it was an amateur electrician.

[@Skyhawk1998]

John Howard even if a switch is off it might be breaking the circuit from "downstream" of the device or room, not from "upstream", which means the device will deactivate but there will still be power going to it.

[@MrMichaelLudgate]

For sure... "hide the evidence" :D

[@ExperimentIV]

i expect you’re about to get a bump in views and shares on this, considering that hypebeast have just held another event in Hong Kong using UV-C as decorative lighting recently

[@icemaiop]

Same thing happened to me. I couldn't find any UV lights in my area for quite some time, and when I saw that they were selling UV lights in a nearby store I went and bought 3. I noticed that they were different, clear tubes labeled as antibacterial UV lights. The guy in the shop turned them on and they seemed a little weak, but I bought them anyway. When I got back home I wired them up to test if they work and turned them on for 2 minutes. After that I went straight to bed. 4 hours later I wake up and can't open my eyes, they are burning, tears are running down my face and my eyelids can't open no matter how hard I try. It felt like someone filled my eyes with superglue. So I was there laying in bed for 1 hour in pain trying to open my eyes. After one hour I managed to slightly force my eyelids open, just enough to see where I walk. So I went to my kitchen and my mother was sitting there with my aunt drinking coffe. They were shocked when they saw me, my eyes were blood red and my lips trippled their size. So we went straight to emergency and they gave me 4 alergy and blood pressure injections. Next morning it was still the same, so I was thinking about it and thought myself "what if the UV lights burned my eyes" So I googled it and turns out that the symptoms were the same as of welder's flash sickness. So means I had arc eyes. I went back to the emergency and this time they prescribed me some eyedrops which really helped. But I felt a slight burning sensation on my skin for the next 3 weeks.

[@PapaWheelie1]

S Core - ouch. Did you come down with a cold several days later? I have noticed that in closed areas with lots of ozone, it reduces your immune system. I was in a classroom where we built a bunch of large Tesla coils and ran them, smelled of really strong ozone, we all got sick in the following weeks.

[@icemaiop]

PapaWheelie No as far as I remember I didn't catch a cold. That was back in June and I wasn't sick since then.

[@icemaiop]

Funny thing that happened. The following morning I was sent from the emergency to the main hospital, and was sitting on the bench waiting for the morning shift to begin because I was too early there. Back then I was still unsure if it was some sort of allergy or if the UV lights caused it. A nurse came out of their hospital wing heading home, looked at me and said "Have you been welding?" with a wide grin on her face.

[@PapaWheelie1]

S Core - ozone must not have been too thick then good - take care man and thanks for the warning

[@fohdeesha]

Damn! That's a cautionary tale if I've ever seen one! Glad you turned out ok. No permanent eyesight damage?

[@peaceone9733]

I’ve used a portable black light for hunting scorpions in the desert at night, and more recently a UV LED flashlight. The fluorescence of the exoskeleton makes them highly visible and easy to find. No one knows why they evolved to fluoresce.

[@microTrash28]

I figure it could just be a coincidence. Their exoskeleton just so happens to fluoresce under UV.

[@ericplatt6884]

@@microTrash28 Could be. But they could be operatives of the aliens - the one's whose UFOs shoot out purple UV beams all over the desert at night...

[@alkallne-koh]

​@@microTrash28it's to reflect the hot sun 😊

[@microTrash28]

@@alkallne-koh That makes a lot of sense.

[@skywalksgaming]

In UV nomenclature, the letters are as follows: A = Altered B = Burned C = Charred You don't want to get anywhere near UVC unless you want to become a crispy critter.

[@moraleza5141]

loved it.

[@ddAAntes]

C = Cancer

[@soup5344]

C = "clean"

[@joshbarney275]

@@moraleza5141 qwwwttetrrtyddteyshq vfhwgsfcacwcfgvuuhhubwiy asdyva yv ga yyss us gnywnwthywytreeeeehywh

[@rickharper4533]

@Josh Barney u good? Do I have to call an ambulance? It sounds like you are having a stroke

[@papercut2008uk]

There was a case years and years ago i remember hearing about. A woman who wroked in a butchers started to get blistering on her face, after loads of tests and stuff, turned out to be the manager who changed the UV bulb in the bug zapper for a cheap UV bulb that was burning her skin.

[@thomaslevy2119]

I once worked for a filtered water vending machine company. (Where you take your own bottles to fill.) Their machines used ultra violet sterilizers as part of the reverse osmosis filter system. The high-output UV tubes were three feet long and housed inside a stainless steel box. Water flowed through clear quartz tubes next to the UV tubes to be sterilized. I was told the UV would kill some bacteria, but not all. However, the UV would damage the surviving bacteria's DNA so it could not reproduce. For safety, the enclosure had an interlock to switch off the UV lamps when the cover was removed. When the UV lamps eventually burned out, the machine used a current sensor that shut the machine down until the lamps were replaced to avoid dispensing unsterilized water. The main problem with the machines was that they tended to leak from their many internal plumbing connections. The job kept me busy.

[@nigeljohnson9820]

Thomas Levy it is my understanding that UV, or rather the ozone it produces, is far more effective at killing cryptosporidium than chlorine or chloramine, which is why UV is now used to sterilise drinking water in addition to adding chloramine.

[@thomaslevy2119]

When the water machines were originally designed, ozonation was the standard for sterilizing water. However, our company needed a cheaper way to do it for the stand-alone machines. UV was chosen as it is simpler and less dangerous to handle than chlorine. The company also bought out a competing filtered water outfit who used a smaller, but more efficient vending machine. Its single UV tube was mounted inside a water jacket that allowed the water to come into closer contact with the UV source without the extra glass tube in between. Their machines broke down much less often, too. Unfortunately, the company decided to do away with the better designed machines for standardization. Naturally!

[@thomaslevy2119]

Soundspark: Correct. To try to keep my reply brief, I did not mention that the UV tubes were replaced on a regular schedule -- unless any of them failed before that. These were special UV tubes which looked more like neon tubes having only one terminal on each end. I was told they were quite expensive and the company replaced thousands of them every year.

[@Hi.Al.]

Friends, if those words are correct ", the UV would damage the surviving bacteria's DNA s " then that machine is making super-bacteria's . The explanation is long but to make it short: bacteria don't reproduce like humans, they don't need an opposite sex mate. They reproduce by themselves . So if you damage the DNA they're single purpose is to survive and they will recombine DNA so the next generation won't be affected by UV or who knows what malefic purposes will they develop with the help of that UV theory.

[@herpnderpn2484]

@@Hi.Al. I would agree that it may not kill all and only damage the bacteria, but as a counter point there have been no incidents that garnered much attention. I would also argue that one of the few things we do know is that unfiltered (no atmosphere) sun light kills everything in short order.

[@onstagesolutions947]

As a person with an unnaturally high number of UV lights in my life due to my weird obsession with things that glow, I very much appreciate this informative video! Lots of good information

[@sandersliam]

Medicinal use 😂

[@thepjup4507]

you have a collection of tritium tubes?

[@hadleymanmusic]

Where can I find a white paint that glows white?

[@Shonade_Malik]

Just make sure to not kill your braincells and put strain on your eyes.

[@rapunzeleh546]

when we were kids (about a billion years ago), we actually played with liquid mercury at school... and apart from forgetting everything, and peeing my pants three times a day and forgetting everything, it didn't seem to have done any damage.

[@Ea-Nasir_Copper_Co]

You don't want to do that as an adult, if you wear a wedding ring!

[@tydshiin5783]

@@Ea-Nasir_Copper_Co a platinum ring to be specific

[@Roy_Tellason]

@@Ea-Nasir_Copper_Co Mine got "amalgamated" while I was doing some contract work for a dental supplies company.

[@davidcoghill8612]

A problem with the UV tubes used in tanning salons, is that over time the coatings on the inside of the tube breakdown and they begin to allow (low levels of) UVC to pass through. The manufacturers usually suggest a lifetime of 1000 hours at the very most before the bulbs should be replaced, but you can bet that most high-street salons aren't counting and only replacing them when they either fail or become obviously dimmer.

[@bigclivedotcom]

The tubes tend to get hammered for maximum output. They trade off lifespan for a higher intensity.

[@UltimateDIY]

Clive, I'm really glad you made this video, because very few people know how dangerous some types of UV can be. A few years ago I almost blinded myself with some UV LEDs of unknown wavelength. I ordered white ones, but the seller sent me UV ones by mistake and I decided to keep them any see if I can find a use for them. I made a sort of UV projector with about 100 of them soldered on a test board. I powered the thing on and everything lit up around me like a Christmas tree. After a few minutes my eyes started to hurt really bad so I turned it off in panic. The pain went away after some time and I thought that all was ok, until the next day when talking to my mother I realised that in a certain area I wasn't seeing her face anymore. It was really weird, because it was not a black spot or something, it was just "missing visual information". The blind spot was maybe the size of half of my palm at arms length. I have no ideea, even today, why I did not go to an eye doctor, but luckily this problem went away by itself after about a week. Now I realise that if I would have kept those LEDs on for a few minutes more, maybe I could have done some serious and ireversible damage to my eyes and this freaks me out when I remember the whole thing. From all of this I learned that you should never play with anything that emits UV, unless you absolutelly have to, and even then wear all the possible protections!

[@psirvent8]

Those LEDs were most likely UVA and these particular wavelengths do indeed cause retina "sunburns", which basically mean black spots. Even blue light without any UV is harmful for the eyes. Be careful with UV, blue and white LEDs. Be also careful with blacklight tubes as they emit... you guesses it UV ! (UVA to be more precise).

[@Blazer02LS]

One of my first exposures to UV lighting was a wedding reception at a bar. The bride came in and was still wearing her gown. The snow white gown however was invisible. Unfortunately for her the lingerie she was wearing under it must have been treated to make it VERY visible in UV....

[@ornessarhithfaeron3576]

Trashy

[@rmx4087]

Modern leggings show through under bright sunlight. 🤣😂 And yes some women don't wear panties.😯

[@Blazer02LS]

@pepperSnakes True. She didn't know that most white clothes are treated with an enhancer that makes them show up as "bright white" or that it had the bad side effect noted above.

[@adamreiss4548]

I worked as an electrician at a meat packing facility. The air handlers on the roof had uvc bulbs installed to sterilize the air coming in. They were 4' bulbs, and they had a very visible bead of mercury inside. These were new bulbs received in 2016. Our HID bulbs also had visible murcury inside.

[@jasonhamilton5756]

Clive, those ones that cause skin damage are great for water processing. They kill all the bugs in the water that cause sanitary problems for people, as the water flows through the treatment chamber and without chemicals being added. It's super neat stuff to work with. The ones I worked with where encased in quartz sheath that protected the bulbs from the high pressures. I love that you covered this sort of application. Great vid Clive.

[@donaldasayers]

I remember a club bar in Newcastle when I was a Student (Late 70s.), that was lit entirely by the fluorescence of the quinine in a row of tonic-water bottles, lit by UV. I thought it was really cool at the time.

[@Sylvan_dB]

germicidal tube is (or was) also used to erase EPROMs thru their little quartz window on top of the chip. UV LEDs are available, but it is hard to find the ones that put out enough UV to excite hi-vis clothing (or laundry brighteners or bio stains, etc) like a "black light" tube.

[@phils4634]

CREE do good ones - long wave UV torches (popular for money checking, and also very popular with Mineraologists / Geologists). Pretty short lifespan in comparison with "usual" white light LEDs

[@Bluemoon_19]

we use this at work. it lights up uv spary we put on boxes to get the right amount per bundle. uvgear.co.uk/product/product340.htm

[@3zuli]

There are some very cheap "365nm" flashlights on ebay. I have one of these, but I would be really interested if it really is 365nm. At this price, there has to be a catch, as quality UV flashlights go from $50 up. www.ebay.com/itm/Zoomable-Led-UV-Flashlight-Torch-Light-365nm-Ultra-Violet-Blacklight-AA-Battery/112056431233

[@Aslyuriel]

I recently bought 100 300nm UV leds.

[@ChurchOfTheHolyMho]

Apparently the UV flashlights stocked at WalMart are 400 nm. Great for confirming what you already know about that discount hotel room you've chosen.

[@garethevans9789]

It's harder to find a vein to inject under blue light. When I was in A&E I noticed the intense blue light in the toilet, so I asked the receptionist. I was pretty surprised.

[@ZT742]

Gareth Evans It’s pretty easy to get round. Some cities paid loads to install blue lights in all their public toilets, so all the druggies started marking their veins with a biro before they went in...

[@draven4464]

Because instead of addressing addiction scientifically, let's just gloss over the issue by removing the means

[@censorthis-uu6cc]

Cin Lee - its not even removing the means - users will likely just do their best in the conditions they have, probably missing the vein in the attempt and doing much more damage than the drug itself would do, resulting in abcesses, infections, and possibly amputation & leading to extra social & healthcare costs. A policy of 'harm maximisation'. But at least the proponents can feel a smug sense of accomplishment that they have inflicted some misery on those they despise, despite the larger cost to society.

[@briank592]

@@censorthis-uu6cc this is the problem with some people and their desire for managing society via bureaucrat decrees. Disconnected people in politics think we as humans are just chess pieces, and we can be moved how ever they want, and we will predictively act according to their studies and theories. Its sad how low level thinking these city planners and politicians are. They think if they declare x, then y must happen. But humans are creative and adaptable. They think taxing the rich works? The rich adapt and hide their wealth differently. They think uv bulbs prevent junkies from finding the vein? Junkies adapt and bring a marker in to chart the vein or use a lighter to see it better. Ok, well do planners and politicians adapt to further attempt to solve the initial prb? Nope. We did our decree, and our jobs done. Next issue. Move on to the next pork belly expenditure.

[@GenBloodLust]

I was at a rave once and woke up the next day and for a couple days and my eyes felt like I had been playing around on a beach, but i live in Tennessee nowhere near a beach in the middle of December. Maybe thats what happened

[@allseeingeyezz]

could have been the LSD

[@Paul-gz5dp]

It was...

[@megganchappel2196]

About 7 or 8 years ago my parents bought this strange contraption. When I asked them what it was they said it was an air purifier to keep germs from spreading. For the longest time I never knew how it worked. After watching this video it all makes sense now! The light it used is UVC light. It had all the signs of UVC; ozone smell, only use it when people aren't in the room, don't look straight at it or expose skin to it. Thank you BigCliveDotCom for these amazing informative videos! Keep up the good work!

[@twocvbloke]

I remember something on a BBC programme (EDIT: Turns out it was Bizarre E.R. on BBC Three) and there was a case where some kitchen staff were coming down with the symptoms you described with skin burns, eye troubles and other things, they examined the kitchen thinking it was chemical burns, but after several investigations they couldn't work it out, it was only after it failed to light that they found someone had replaced the tubes in the kitchen's fly zapper with the germicidal tubes, resulting in the damage to the staff...

[@erezra]

UVB/C is sometimes used in geology where the minerals fluoresce only under short wavelengths (~250nm)

[@phiksit]

I wish he would have covered which wavelengths / bulbs are best or what... like examining currency, finding pet stains / blood residue and curing uv setting glue, etc...

[@hellrazor117]

Also for indoor growing. Certain plants will try to protect themselves from UV A/B by producing more resin. A good way to increase potency.

[@ps3master72]

@@hellrazor117 "certain plants"

[@lynncheetham1878]

Another quality video, you beat the entire terrestrial UK TV menu at primetime yet again.

[@SianaGearz]

That the plastic lenses don't block UV while glass does is a myth. CR-39 and PC are naturally somewhat transparent to UV-A, but block lower wavelengths. PC for prescription lenses is modified to block UV quite sharply, and CR-39 comes out porous and the UV protection is added to the sealing resin that the surface is treated with. Trivex and high-index optical plastics are also engineered to block UV. PMMA is an interesting case, it's largely transparent in UV-A, severely attenuates UV-B, and has a very surprising UV-C transmittance window, up to 40% at some wavelengths, and i'm not 100% certain, but i think it just narrowly misses the germicidal tubes, which should be 254nm, while it has a transmittance window around 260-270nm. Haven't heard it ever being used for prescription glasses, though it is possible, it is certainly a valid optical material.

[@HiruS22]

Siana Gearz Was reading down the comments to see if someone would point this out. You should have been wearing specs with PLASTIC lenses Clive, glass ones will not give the same protection from UV!

[@SianaGearz]

Well to be fair the Schott glasses that they use for glass lenses are also engineered for a sharp UV cutoff nowadays, but this didn't quite always used to be the case. I think the myth originates from comparison of greenish window glass that isn't used for lenses with PMMA. If you replace your house windows with Plexiglas, you can get a tan, and it can even get dangerous if you're under an ozone hole.

[@halbvoll1]

My first experience with a UVC Lamp was in an EPROM reset tool, the EPROM has a small round glass window where you can see the inside of the chip and it resets when UVC Light passes through that's why there has always been a sticker on it to prevent it from slowly getting resetted

[@SamZeloof]

Also, the UV - C bulb may have a lower pressure of mercury vapor in it. Lower pressure Hg lamps make only 184 nm and 253 nm, of which the 184 is always blocked unless the tube is quartz

[@SamZeloof]

higher pressure lamps like used in projectors and for lighting have a more broad spectrum and the bad uv is blocked from the borosilicate glass enclosure

[@wdavem]

I've seen large clear UV tubes used in science labs for killing germs, bacteria etc. The light switch (for just that tube) is outside the lab and has a big red indicator and a warning to prevent exposure to that light. Thank you because this is a very important video. I've been told 'if it smells like ozone near a lamp and you don't know what that lamp is, prevent exposure'.

[@smudgerdave1141]

Hey Clive, nice video. I'm surprised you didn't mention optical brighteners in washing powder that make clothes seem ultra-bright under black-light-blue lamps and I'm also surprised you didn't mention that the insectocutor-type (white phosphor) lamps are the ones you should buy for your photo exposure box for making pcb's with photoresist boards.

[@bigclivedotcom]

Technically speaking the blacklight blue may work for PCB exposure too. I'll have to give that a go.

[@nodularprurigo]

The other main use of UVA & UVB that was not mentioned is in phototherapy for skin conditions. Specialist tubes for precise wavelength control.

[@JerryEricsson]

The old insect killer that I purchased back in the early 80's was designed for farm industrial strength work. It did not fry the bugs, but had a fan that blew the insects into a sort of burlap bag, where they were collected, the fan was rather slow but fast enough to keep them captive, and probably kill them on the way through, it did have a circular black light in the top to attract the bugs into the death fan.

[@CassetteMaster]

Very interesting presentation on UV lamps! My favorite use of UV-C is erasing EPROMs!

[@erictaylor5462]

I took a black friend skiing once. I offered him sunscreen but he didn't use it. The next day he called me saying his face felt like it was on fire. He'd sunburned his face. And he was quite dark skinned.

[@brentfisher902]

A lot of people don't realize that the sun reflecting off the snow can cause a sunburn even in the winter...

[@emilychb6621]

@@brentfisher902 Yep, both water and snow on clear days are quite nasty if you don't wear any protection. And it doesn't need to be 'hot'.. Especially in the mountains, where there's even more UV, and may never rise above room temp anyway.

[@jonathantan2469]

@@brentfisher902 There's also risk of eye damage from UV light reflected off the white snow. Skiers, alpine trekkers, & snowboarders would know this. Eskimos historically made special goggles from bones or tusk, with small holes carved in them.

[@techobsessed1]

@@emilychb6621 Cloud cover doesn't attenuate UV as much as it attenuates visible light, so cloud cover is deceptive when it comes to judging UV exposure. UV exposure also increases with altitude due to having less atmosphere to attenuate UV. Finally, sunscreens often offer some protection against against low humidity and wind in the cold mountains. Both are bad for the skin, especially in combination with UV exposure. Eric's friend had a lot going against him.

[@schnoodle3]

@@jonathantan2469 Called Snow Blindness

[@HarleyBadger]

I was wondering if you have ever looked at GTL3 germicidal UV lamps, they look like regular E14 screw-base clear incandescent night light bulbs. I bought three of them for replacement in a vintage "air purifier" that is absolutely tiny and has very little airflow, yet is claimed for use in entire homes. The air purifier isn't really filtered, it's sort of just a small fan with a cluster of these GTL3 lamps. I have a sort of strange suspicion now, after viewing your video, that this antique air purifier may actually be functioning as an ozone generator.

[@waynedombrowski7568]

I use these lamps for my fluorescent mineral collection. Different minerals glow under either uv-a,b or c.I use a black light blue(also called uv longwave) and the germicidal(also callled uv shortwave).Only recently we've been using uv-b(midwave). The most expensive part of my hobby is the filter for the uv--c. You need the filter to block out the visible light but that lets through the uv. I'm talking hundreds of u.s.d.. but oh,they're awful purdy! If you're curious,KZbin has a few clips under'fluorescent minerals', 'Franklin,New Jersey' and 'Sterling Hill Mining Museum'. Also,most Natural History museums at least have a modest display. Be careful,though - it can become an obsession. Trust me.

[@psirvent8]

Hello, How do you protect your eyes while using the UV-C light to make minerals glow ? UV-A will not cause much issues if it's of a low enough power, however the same can't be said for UV-C which will cause eye burns just like welding arcs if you get even a few seconds of exposure. In fact germicidal tubes should only be used in the absence of people in the room to be sterilized.

[@peterjameson321]

A great video as always Clive. It's so important that people should be alerted to the very real danger of UV and in particular UVC. It's worth mentioning too that even intense blue light is bad for the eyes in the long term. There's plenty about this on Google. I once stuck a yellow sticky note over a brilliant and very annoying blue LED on my computer monitor. Within a week or so, the blue light had bleached a white patch on it indicating that the yellow pigment in the paper had been destroyed.

[@ELECTROHAXZ]

Thank you Clive for this video! I remember once I was at a sort of thrift shop in the US called Goodwill, and there was a device that was about 6 inches long and looked like a small chest, but I noticed the lid of the chest had one of these clear bulbs in it and was powered by some batteries or power supply, I forget now, but it was a low voltage florescent tube driver and I considered buying it just for that cool tube and driver circuit as I had never seen a clear tube before and I wanted to know what was inside, I am very glad I didn't as that tube was one of these UV C ones as well and I would have not known about that and possibly used it as a cool light for accents or something. Thank you for making awareness about these tubes and keep up the great content as usual :)

[@davidescicolone8069]

I heard "germicidal" as "genocidal" at first

[@samschannel531]

with UV-X, it can be both.

[@tolga1cool]

Well. It's a germ genocide isn't it

[@jismeraiverhoeven]

Well it depends on how you use it right? Im sure enough uvc can be lethal, so exposing everyone to loads of it is genocidal

[@csinscorrections5934]

Oh the sand in the eyes feeling I rember from my younger years from wielding

[@psirvent8]

Without mask ? 🤔

[@RickinBaltimore]

This just happened again at a Bored Ape event in Hong Kong recently too.

[@darylcheshire]

maybe take it with a grain of salt but Claude Monet the impressionist artist had cateracts and had an operation to have them removed. His later paintings had a reddish tinge which apparently was due to him seeing the UV spectrum.

[@GnightOwl]

Just discovered you man I love your attitude and wisdom I'm a younger guy, worked in electrical for 5 years. I appreciate any knowledge you spread

[@paulyh4531]

Excellent video Clive , I can imagine a lot of people prob buy the wrong bulbs just to save a few pence not even knowing the hazards ! This is the sort of thing del boy would of flogged as display cabinet bulbs lol

[@electronash]

Pauly H Still remember the first time watching this. I must have only been about 7. lol kzbin.info/www/bejne/sHS5Z5J8gLWogaM

[@JohnHi6]

Loved the video Clive, it got me wondering about uv LEDs used in some lights/torches. I use the uv curable glue and the standard uv led you get with it isn't that powerful so I tend to use a violet/uv laser pen which cures the glue very quickly but the exothermic reaction is greater as the glue goes off. But neither my led torches or the laser will cure K300 uv resin which cures to a flexible finish, only a few hours of daylight seem to cure this one? Is it true UV you get from these LEDs or just violet light close to the uv spectrum? BTW I use yellow goggles when using the uv laser to prevent the back scatter which are plastic, should I get glass one's? Cheers and ATB John.

[@JohnHi6]

Loved the video Clive, it got me wondering about uv LEDs used in some lights/torches. I use the uv curable glue and the standard uv led you get with it isn't that powerful so I tend to use a violet/uv laser pen which cures the glue very quickly but the exothermic reaction is greater as the glue goes off. But neither my led torches or the laser will cure K300 uv resin which cures to a flexible finish, only a few hours of daylight seem to cure this one? Is it true UV you get from these LEDs or just violet light close to the uv spectrum? BTW I use yellow goggles when using the uv laser to prevent the back scatter which are plastic, should I get glass one's? Cheers and ATB John.

[@willrobbinson]

UV leds are still struggling to get to the shorter wave lengths at energy levels needed for this purpose

[@TheMatthooks]

Remember, most of it is non-visible, so it might not LOOK very powerful, but there could still be a lot of dangerous energy being emitted!

[@mikebeagan3795]

This reminds me of the mid 90s when blue silk blouses were all the rage for young ladies. While at a gathering at a friends house we discovered that the black lights he had set up for some posters rendered those blouses completely see through. The young ladies in attendance were not amused by this bit of scientific discovery.

[@joinedupjon]

Mmm the smell of bleach and singed bacon - the essence of a fashionable night out hong kong style. I was sure you were going to mention the optical brightening dyes used in laundry detergent to make shirts look whiter than white at some point... but it never came.

[@wingerrrrrrrrr]

The singed bacon demonstration in this video was unexpected. Even for the sake of science I wouldn't want to do that just for the KZbin vids.

[@12voltvids]

I use a UVC germicidal lamp in a tooth brush sterilizer. PL9 UVC in a wooden box with an interlock switch to prevent it from operating when open.

[@G1SUNPLANT]

Thorough explanations of UV lights! Thanks a lot! Cheers!

[@minxythemerciless]

The really good UVB is 311-312 nm. It's called narrowband UVB and it has a remarkable effect on the immune system calming it down especially for skin diseases eczema and psoriasis, but also for general suppression.

[@VernKlukas]

Just a clarification on the mat hatter thing. Hatters weren't working over a hot pot of mercury to shape hats-they were treating the raw fur with mercury nitrate solutions during the felting process because it made a superior felt for a hat. The process involved heat and of course plenty of mercury vapour. Yours Vern

[@louistournas120]

I don't think you get mercury vapor by heating mercury (II) nitrate. Were they heating it to the point of decomposition or the melting point (79 C)? The danger is that it is a water soluble salt and so, it can pass through the skin. Mercury, lead, cadmium salts are dangerous to handle with no gloves on.

[@andreccantin]

I wonder if the UVC lamp would cause rapid yellowing of plastics, like nineties white/beige computer boxes that have gone yellow. If so, it would be interesting to see how well other plastics will age. "What will this look like after 20 years of sitting in a windowsill? Let's find out!"

[@Synthematix]

with hydrogen peroxide and uv light it can actually reverse yellowing.

[@ethanpoole3443]

André Cantin It is not so much the plastics themselves that generally yellow but rather it is usually the result of the flame retardant additive that creates surface yellowing when exposed to UV light (typically a mix of extended blue and UVA light exposure). If you oxidize (bleach) the plastic (such as with hydrogen peroxide) you can bleach the yellow out of the plastic...until the next time. Which would make UVC an interesting experiment since it will be both attacking the plastic's flame retardant, causing yellowing, but also generating ozone that may bleach it out at the same time. Could be an interesting experiment if proper safety precautions are taken since UVC can be rather hazardous to living beings.

[@agvulpine]

You may be onto something for technical antiquing of certain materials. It's definitely worth an experiment. You'll get the double whammy of UV exposure, plus O2 (oxygen) that has been radicalized into loose O3 and free O's ready to bind to organics to age them, or to metals to oxidize them. I've wanted to build an arc O3 generator for experimenting with rapidly breaking down different materials. Finding a robust high-yield design on the internet is tricky.

[@SeanBZA]

It does, the holders for all flourescent lamps are made from UV resistant plastic, and they generally get very brittle after less than a year of use, plus you can see the chalking and brittle plastic in comparing the side facing the tube and the shaded back side. They tend to be very brittle after a year or three of use, and shed the glass or chalk filler from the exposed surface with only a touch.

[@SeanBZA]

Might make the plastic white again, but also makes it a lot more brittle as well, simply by breaking and reforming new bonds that make it less flexible. You see the result as surface crazing when you stress the now white plastic.

[@subron14]

Thank you, very informative. I was posted in the Holy Loch U.S. Navy 1972. I loved Scotland and the great hospitality of the folks there, the beautiful scenery and history.

[@hullinstruments]

Another use for enclosed UV sterilizing lights are in high end ice machines. They have an enclosed metal box with a very small but intense UV light. There’s a groove or channel that guides the water to flow evenly in front of the light and be decontaminated. They must work well because it’s regulation here in the states in many places… And they are several hundreds of dollars for the unit. The bulbs usually about 120 bucks to replace and it’s only about 6 inches long. Manitowoc and other big companies like Scotsman and such… That’s who use them. I love black lights because I enjoy hunting for radioactive items to add to my collection. A good geiger counter and scintillating probe with survey meter make it really easy to find radioactive items from several meters away.… A good scintillation probe is at least 100 times more sensitive than a geiger tube. It can pick up dense uranium deposits from hundreds of meters away. Hell they still strap them on helicopters and fly over looking for uranium deposits… And they’ve been doing that since the 1950s. Sorry to ramble… Backto lights.... I keep both a 365nm and 395nm UV flashlight with me at all times. They can be had for five to $10 each… But I highly suggest looking at the “convoy s2” uv lights. There must be one big factory in China who makes the exact same light and then convoy and others brand them with their name and a few key features. Convoys version is around $25 and worth it if you’re serious. but the same light can be had for about 10 bucks my other companies, but the attention to detail and quality control isn’t as good. Those lights really do kick ass I love them! It’s a blast and modify them with different LEDs and test out different control chips.. 365nm is important when looking for things like uranium oar, antique uranium glass and marbles, prospecting for fluorescent minerals or interesting things when Beach combing, many species of fluorescent animals like scorpions and other bugs… And of course pet stains and checking to make sure the hotel room was cleaned well. Don’t bother buying one of those massive Cheapo UV flashlights from Amazon with over 100 LEDs in them or something dumb. The convoy S2 has a single UVLED and it’s brighter than any of those shit lights. And you can’t go wrong with 365 and 395 nm. If you really want one of those Amazon lights… They pretty much only come in 395 nm so you can still get that just be sure to get a 365 nm also because it’s the most important. If you really want to go crazy… Look up “way too cool” UV lights. They are about 500 bucks but they’re custom built and really do kick series ass.

[@MK-ih6wp]

Can you help me? I'm looking for an affordable black light that will help me clean up after my 2 kitties? They're getting older so litter box mishaps are happening more frequently. My biggest fear is I'm going to become such a crazy cat lady that I will fail to notice some out-of-the-box cat pee, & that awful urine smell will seep into the surfaces of our house. Permanently. *yuck*

[@MK-ih6wp]

I'd bought a very cheap uv flashlight from walmart but it doesnt work at all for detecting cat piss. Thinks it's a Rayovack, w a pink purple metal flashlight body. Someone said I might need to wear certain glasses to make it visible w that specific flashlight. But that doesn't make sense to me.

[@chrisreynolds6331]

Thank you for the tip I will never go anywhere near a clear tube if it’s energised. Pretty scary when you think about it a small current passing through the mercury vapour can actually change the structure of matter around it!

[@CKOD]

Good video and interesting incident in hong kong. Makes you wonder about the attention paid to safety of event goers. At EDC (big rave in Las Vegas) I found myself taking notice of some of the practicalities for the crew doing sound and light effects. Some of the stages were under a big arch, so stuff like laser effects were quite common as they could land the lasers on the canopy. Occasionally there would be a big laser display over top the crowd in one of the big open-air stages and it would be "Holy shit that looks amazing.... wait where the heck is that landing?" look back and it would usually be the signs above the perimeter of the raceway, or in cordoned off areas of the bleachers, occasionally somewhere clever. In comparison to rinky-dink venues where lasers land all over the place including down in the crowd. Really makes you appreciate that the lighting guys arent just hefting gear and cables, but also vital to peoples safety at an event that's supposed to be recreational.

[@bigclivedotcom]

The laser standards at professional venues are strict about not allowing direct eye contact. In cheap clubs it's not uncommon for DJs to point powerful lasers directly into the audience.

[@CKOD]

It would be interesting if you could get your hands on a pro laser effects unit (something nice like a laser equivalent of the PRG lights you were able to show us) and compare it to an ebay special. Its been a while since Ive looked into them, but don't the real pro units have safety stuff such as stuck/faulty galvo detection, physical stops to prevent the beam going into the crowd, etc? Plus I'm sure a liquid sky in your dining room would make for a nice dining experience.

[@TechBench]

"Its been a while since Ive looked into them..." Don't look into laser with remaining eye!

[@buddyclem7328]

TechBench *NICE!* It's all about the timing. (Accidental pun.)

[@erictaylor5462]

That eye damage is EXTREMELY painful. Feels like you have sand in your eyes. Fortunately, so long as the damage isn't too bad, it heals quickly. But man does it hurt. I burned my eyes once while welding.

[@erictaylor5462]

@Christopher Grant You can still burn yourself even with all that equipment. I've never done it myself, but I have seen it done.

[@psirvent8]

Did you have your shield on back then ?

[@hedgehog3900]

Utterly fascinating. You put some sparkle into a humdrum sunday evening. Thank you big man.

[@RaymondJerome]

the germicidal ones are also used in old EPROM erasers. i once set one up in a file cabinet and had it on for a month exposing test samples of clear plastics 1-6, do not have my notes but vinyl turned a nice yellow, something else, possibly styrene turned into a very brittle thing that was solid till you touched it.

[@YouLCD]

aquariums often have a uvb tube... turtles need it for their shell to develop/harden their shells apparently also aquarium filtration systems use uv tubes to kill bacteria

[@THBfriend]

To be more precise, and repeating what Clive explains in the video, the ultraviolet part of the spectrum is commonly divided into three subranges (from low to high energy): UVA, UVB, and UVC. The bacteria killing UV that you mentioned is UVC, and luckily it's strongly blocked by our atmosphere. UVB can cause sunburn and skin cancer, but turtles (including tortoises) need some small dose of it for the same reason that humans do: vitamin D3 production. Vitamin D3 is made in the skin under UVB exposure, and it plays a key role in calcium absorption, which is of course very important for shell/bone growth. Unlike normal humans, turtles/tortoises can also see UVA. Therefore, when kept indoors, they require an appropriate lighting setup that includes UVA and UVB. Outdoors, sunlight will provide it, better than lamps can. If you do need UV lamps for your reptiles, stick to the known reptile accessory brands (Zoo Med, Exoterra, Arcadia, Zilla, etc.), and don't buy noname products from China or elsewhere, because there are bad lamps out there that will harm their eyes and potentially even blind them.

[@YouLCD]

thanks for the advice, I just recently had a turtle given to me so I have been researching the various types of lighting they require, the tube I got was a uvba&b type so presumably it's as Clive mentioned; uvb tubes are mostly in the a spectrum anyway. one extra question while you're here: the uv tubes seem to have a number next to them, like a 5 or 6 or 10. I got a 5 (and it was a good brand) is this appropriate for turtle basking light? I take her outside when the weather is warm enough too, seems like a good idea to try and replicate the natural habitat as closely as possible

[@THBfriend]

Yes, the UV fluorescent lamps for reptiles all have combined UVB+UVA output, and UVA makes up the larger part, as with sunlight. The 5 and 10 numbers (or 5% and 10%) are indicators of the UVB amount, but these classifications are quite meaningless beyond the fact that a "10" lamp is supposed to emit more UVB than a "5" lamp, and would therefore be more suitable for animals that are exposed to stronger sunlight in nature (e.g. in deserts). The big brands usually have some guidelines on their websites that tell you which lamp is suitable for which species. Distance between lamp and animal, and presence/type of a reflector also strongly influence how much UV arrives at the animal. If you want to be absolutely sure, there's no way around buying a UV index meter (better than a pure UVB meter), and measuring the output of your lamp at the appropriate distance yourself, then comparing it to the UV index that the animal would experience in the wild. The Solarmeter Model 6.5 is a good meter, but unfortunately not cheap (around $250). Since vitamin D3 production is temperature-dependent, you also need to co-ordinate your UV lamp with a heat source, e.g. an incandescent basking lamp, because fluorescent lamps don't produce significant heat. There are also mercury vapor and metal halide lamps for reptiles, they're all-in-one lamps that produce UVB, UVA, visible light, and heat. I'm using one of those for my tortoise hatchlings nowadays, instead of fluorescents.

[@YouLCD]

hmm yeah, I'm the type of person that would like to have light spectrum, water quality, filter water flow, temperature etc sensors monitoring the tank but well.. might take a while with the cost of some of them. I'll check out the tube manufacturer's website and I subscribed to your channel, I'll be sure to check out any care/ habitat videos.. unfortunately it's hard to find turtle care advice locally so I have been spending a lot of time reading on the internet, thanks for sharing

[@Elfnetdesigns]

Commercial (in store) salt water aquariums use UV C in there filtration systems. I used to work for a company that built store aquariums like that. Consumer (at home) aquariums you have the option to put one in like Clive mentioned Reptile terrariums have a UV lamp similar to the white coated one. Your better lamp fixtures for aquariums and terrariums will have a "Reptile" or"Fish lamp" (we used a cobalt blue lamp" and a "Sun lamp" one bluish tinted and the other as white as you can get..

[@LorneChrones]

Clive do be aware that it highly depends upon the type of glass used. You're probably right because the type of glass in your lenses is one of the stronger types (quartz glass blocks UVA+, borosillicate passes UVA+). But polycarbonate plastic lenses also block UVA+ but they do have the yellowing effect after awhile. (Especially hard to notice if one's PC lenses have transistion/chromatic diffuser coatings on them like mine).

[@NoobixCube]

UV damage to eyes is no joke. On a particularly sunny day, in Australia, I lost my sunglasses, and sank a solid day into some summer time yard work. I got a small amount of that "sand in your eyes" feeling for the next few days (more a minor irritation than a serious discomfort, in my case), but the real kicker was the photosensitivity. The following day, and for more than a week after, going outside was out of the question, during the day. After that week, it was just moderately painful. Just reflected sunlight off cars and other metals felt like someone was shining a spotlight into my eyes. For several months, nearly a year, every time I left the house at night, I wore strongly polarised, though not terribly optically dark, sunglasses. Street lights, and car headlights would blind me completely, without those glasses. Moral of the story: look after your eyeballs. They will punish you for your carelessness.

[@psirvent8]

The light sensitivity might be from the UV-A and bright visible light while the sand in the eyes aka photokeratitis is caused by UV-B, the same rays that cause sunburns on the skin. Thankfully they are less powerful than UV-C which might partly explain why you didn't get more severe sand in the eyes. I got eyestrain and light sensitivity for up to a day and a half on some occasions after having played with powerful blacklights at close range without the right eye protection, however no sand in the eyes as blacklights only emit UV-A. My latest acquisition is a 400W mercury vapor blacklight and it really is no joke, you absolutely need to protect your eyes with wraparound glasses or goggles that will block the strong UV-A coming from the bulb if using it at close range like I usually do. When it's hanging 10 meters above the floor at a nightclub it's no more of an issue though because of the inverse square law although people might get headaches if looking directly at the lights still. So I use ski goggles to protect my eyes from the 400W blacklight at close range and they are actually quite effective but that doesn't really surprise me as they are designed to protect against UV-A and UV-B rays that come stronger with high altitude while also being reflected by snow.

[@andrewgregoryfilms3622]

This is precious information!! Thank you so much for taking the time to explain all of this!!! Appreciate it!! 💕💯🙏

[@Screwy9758]

The same happened in a kitchen, (I remember the news item) in the U.K. 30-40+ yrs ago! Someone, (the owner I think it was) replaced the 'burned-out blue U.V's in a kitchen fly zapper, with these types, & it was discovered, because kitchen staff ended up in hospital with severe, unexplained skin problems.

[@itscomingoutofbothends8385]

At night road works sites where they wear white uniforms w/ fluoro stripes paired with the UV flood lamps is like driving past a Daft Punk concert.

[@kirkb4989]

And this has been an episode of "Love Your Epidermis" with Dr. Clive!

[@pflernak]

7:50 I know that feeling. Alas it company policy thats messing with me. 14:20 Mercury is a heavy metal and those tend to not leave the body, so I wouldnt play with mercury too often.

[@kinhodreher]

hi, i started watching your videos 1 week ago. I have to say that I think your work is amazing. I'm Brazilian, and I learn a lot from your videos.Congratulations

[@kinhodreher]

@@coalthedergsune Don't worry teressa, brazil doesn't want you😘

[@Culturedropout]

At my job, we manufacture inductively coupled plasma optical emission spectroscopes (ICPOES's for obvious reasons). The "optics box" has to be purged for a considerable length of time with argon to remove all the oxygen and other things that absorb UV light before you can analyze elements that emit high frequency UV. It's kind of a pain, because if you have to replace anything in the optics, you lose that purge and it takes a couple of hours or more to recover.

[@The06madmax06]

I have a 36w UVc for my aquarium and I decided it would be a right good idea to change the bulb and test the new one without the protective cover on, it done me a right concern the day after as I was in agony and couldn't see at all! The eye doctor said it looked like I had rubbed my eyes with sand paper! He also asked if I had been welding so I assume it's the same as arc eye. Horrible experience and for sure learned my lesson on that one!

[@YodaWhat]

A little dab of Vaseline or mildly medicated petrolatum like A & D Ointment is good for "arc eye". Just avoid the products with menthol in them, like Vick's Vaporub. Never put that on any mucus membrane!

[@user-gu1hl2kx2k]

wtf

[@MushVPeets]

15:19 "Optimized for _use_ ..." might not be the best choice of phrasing :P

[@redsquirrelftw]

As a ginger I tend to stay away from any type of UV light haha.

[@lachlan1971]

I had to put on suntan lotion just to watch this video.

[@gordonrichardson2972]

I have freckled skin, so a bit of sun is OK, but I never get an even tan.

[@brentfisher902]

I heart chubby bearded guys.

[@LittleRainGames]

Why? Does it have anything to do with not having a soul?

[@fadingbeleifs]

mmmmmm Vernors... Made from real gingers...

[@artillerest43rdva7]

the uv A & B we used in accelerated weathering chambers. t12 4’ lamps. great job explaining the difference with the different types. have a great day.

[@Xenon777_]

Big Clive, that I have a little 8w strip light like yours. I got mine from B&Q and made by Masterlight. When the tube reached the end of its life the electronic ballast blew up. There was a pop and smoke. I then bought two Made In England Fitzgerald, New old stock 8w Fluorescent lights and they have been perfect. They have a magnetic ballast and starter. The model is Fitzgerald MLP8

[@hamedasadi4021]

A humble reminder: keratitis not keratosis

[@bobjoe1593]

This takes me way back to middle school bio where the latin suffixes were irrevocably drilled into my brain... itis means 'an inflammation of', osis means 'a disorder of'

[@MarkTillotson]

I had a keratosis, specifically a seborrhoeic keratosis, which is a nightmare spelling question let alone an iritating skin lump. They used a prototype multi-spectral camera at the hospital to help diagnose it before removing it. Such keratoses are common and sun exposure is thought to be a factor - if in doubt about a skin lump, get it checked. Get it checked soon. (I typed sin exposure rather than sun exposure, which I almost left uncorrected!)

[@kwakamonkey]

Photokeratitis (Ultraviolet [UV] burn, Arc eye, Snow Blindness) Chronic sun exposure is the cause of almost all actinic keratoses. Sun damage to the skin is cumulative did clive get them mixed up? he said keratosis in the eyes at 15mins 40 seconds or did i hear it wrong

[@THBfriend]

You're right, it's photokeratitis, Clive probably misspoke.

[@ironman7261]

You should have commented on the danger of those high pressure sodium bulbs which have a bulb inside a bulb. If the outside bulb is damaged the light could appear to be still operating but would be emitting harmful levels of UV. They are being mostly replaced with LED lighting now.

[@lukehennessy3006]

iron man Helpful. Ty

[@bigclivedotcom]

The biggest risk is with the older mercury lamps. If the outer phosphor coated envelope broke then they became UVC lamps. Some had a strike resistor that was designed to fail in oxygen and stop lighting the lamp.

[@petermuller6923]

Ouch. Some years ago, when these mercury lamps still were really widespread in Germany, i often saw such lamps, that some idiots destroyed by throwing stones into them. I can't remember, if these were still burning, but some of these had only the inner bulb remaining.

[@ironman7261]

I saw one continue to glow at work after the outside tube was dripped on from a leaky roof in the freezer and broke. I remember when replacing burnt out ones the warning was on the package the new one came in. We have since replaced them with flouresent bulbs

[@patpflaum]

Professor Clive delivers again. Great Job!

[@carlospulpo4205]

The other use of the UVC bulbs is for erasing the older eprom memory chips. I remember that ozone smell from running an erasing cycle. We used to prop up the chips on static safe foam to bring the window very close to the bulb for a faster erase cycle. The foam would break down within hours of exposure and need to be changed. Having people unknowing exposed to this light is horrible. The eyes will likely suffer the most long term damage, cataract will form prematurely.

[@dazednconfused31337]

On 'Bizarre ER', an insectocutor was fitted with the wrong bulb & it cooked some eyeballs instead. Search Y.T for: Restaurant Kitchen Mystery - Bizarre ER

[@dazednconfused31337]

kzbin.info/www/bejne/iWbOn6Z6ZcetsK8

[@onemillioncats4807]

Dazed AAAA

[@twocvbloke]

That's the one I was trying to remember, thought it was one of the BBC1 morning shows that had it!

[@buddyclem7328]

In the USA we banned "bug zappers" in food service. We still use the bulbs, but now they illuminate a glue trap in the bottom of the devices.

[@rocketman221projects]

If you want some of the white UV tubes cheap, you can get the 9W U shaped ones for a buck each on ebay. They are sold as replacements for the UV nail lights. I use them in my exposure box for making PCBs. They are 365nm, which is ideal for UV curable photo resist and solder mask.

[@bigclivedotcom]

In some of my other videos about PCB making I use one of those nail varnish curing units to expose PCBs.

[@Wanttono]

Thank you, I was looking for a video like this the other day and watched heaps but didn't get a complete picture so thanx for telling us the types and effects of all three, I wanted to know if the lights were different depending on using for water and air and room, so you cleared that up for us. Cheers

[@MrSFSTUDIOS]

Thank you for making this informative video! Now I understand why my blue led strip charges glow in the dark tape so quickly! I always wondered how harmful the regular purple uv lamps are for skin and eyes. Good to know coated glass eye-protection helps shield your eyes. The fact that they subjected crowds at an event to UV-c is frightening.

[@r1w3d]

I LOVE light.. I'm not a fan of the sun but the science behind it is how I ended up with my job as an RF tech. From colours and microwave ovens or range, to communications and my broadcasting work it still blows my mind. Frequency is just freakin amazing to me. I loved this video and thank you for the depth you delved into. 👌A+ content. Stay awesome 👍

[@buckykattnj]

(Watching clear tube light up in video) AHHHH! My EYES! Clive, what have you done?!? ;-)

[@mc_cpu]

It's OK the internet acts as an ozone layer

[@itxi]

Bozone layer

[@robt2151]

Just as well that I've still got a glass CRT monitor!

[@simonhopkins3867]

who said that 😎

[@fadingbeleifs]

your screen can't reproduce it. the camera he uses can't see it. If your phone can produce high energy light like that, you have worse problems.

[@JerryEricsson]

Very nice to know. The only black light I ever had was with the black tube, had it in my barracks room in Nam, lighting up a poster that said "What if they gave a war and nobody came!" in psychedelic colors. Looked great! I had no idea you could be harmed by UV lights, well I knew about the sun and all but not those small tubes. Getting to old now to enjoy such things any more I guess. Oh by the way, I do recall from my time in Advanced training in the US Army, we had a young black fellow who went on adventure training offered for a weekend retreat, he fell asleep on a rubber raft on a lake, and burned the hell out of his back and legs. He was is so much pain, and while in that pain, the Army actually court marshaled his ass for intentional damage to US Property. Man talk about one pissed off black dude! The slavery implications were very apparent when called property, well to him at least. He did finish the course one cycle behind us, as he could not return to training until his burns had healed.

[@psirvent8]

What did the poor black fellow damage apart from his skin ?

[@joinedupjon]

Once upon a time you'd have had to buy these from a specialist shop and have the shopkeeper asking suspiciously you what you were intending to do with them. Probably the ebay vendors don't properly understand what they're dealing in half the time and even if they do they'll spam it with inappropriate words just to get more search hits... probably the manufacturers should print more of a warning on the tubes since that's the distribution channels we have these days and presumably in the future i.e. quite likely ignorant on both sides of the deal.

[@harvestjet]

You mentioned the UV tubes in insect zapper units blasting the insects in to pieces,new regulations now say the zapper units cant be used in food preparation areas (at least here in Wales), insted the tube is mounted in a unit that has a sticky coating that traps the insect.

[@diodedoode]

You have 995k subscribers! So close to a mil! Congrats!

[@zx8401ztv]

Thanks Clive :-D Years ago i bought one of the clear ones, i was making an eprom eraser box. I included door switches to cut the power, along with a big red lit up mains rocker switch. Sounds like i made the right design decision lol.

[@olivialambert4124]

Looks like bad UV might be a little more important with corona-chan coming out to play. No wonder youtube suggested this.

[@thcrtn]

Glad to see some1 smart enough to know #partylights = clean fun

[@ewcm1878]

@Dave William cool story bro. Have some more donuts it helps cure the half brain dead internet police. 😁😜

[@DancingRain]

I guess I'm the only one who noticed this, and that fact makes me sad. But I see this error being made over and over, and feel the need to correct it. The visible spectrum does not end at blue. It ends at violet. hence the name "ultra violet", which means "beyond violet". I've also found the name "blacklight blue" irritating since I first read it while training to be an electrician. The glass is purple, not blue. And don't even get me started on "blu-ray". Other than that, great, informative video.

[@NetRolller3D]

Dancing Rain It's a bit more complicated than that - not everyone can see violet as a distinct color. Some people report just seeing deep blue where others perceive the well-known purplish color known as violet. I believe it's related to certain forms of colorblindness.

[@stargazer7644]

Since we have our pedant hats on, I'd like to point out that the glass is certainly not purple. Purple is a mixture of red and blue. Violet is not the same as purple - it has no red in it.

[@thepcmaniaccc]

I have used a lot the clear ones, they are used in chemistry for analysis. Thin layer chromatography(tlc), there is a aluminum plate impregnated with zinc sulfide which glows bright green when exposed to UVC, you can look it up on wikipedia where I have uploaded years ago a picture how it looks.

[@realcygnus]

Yup good info ! .... as usual. It seems fishy that you haven't reached 1M subs by now(long ago actually), you are a legend after all, even in our minds. 🤣

[@ButterBallTheOpossum]

15:08 you did a good job of walking that tightrope 😂

[@ThePaulius]

"Smells porky" love it. There's a joke there somewhere about the Muppets.

[@A2000MHz]

Clive makes it look like he moves the bulb with telekinesis at 5:36 😂

[@bluephreakr]

Because he knows there is no spoon.

[@MrPruske]

lol'd at this. thank you :)

[@danielhorne6042]

probably a gust of wind he generated from moving his hand ?

[@luisgonzalez5482]

@@danielhorne6042 He physically touches the light.

[@albear972]

Super fantastic and quite informative video Sir Clive! Thanks again for another educative video. I saw you holding the cheap clear one on with bare hands and exposed skin. I always thought they would cause blistering and 2nd degree burns, permanent eye damage almost instantly. Yes, I actually thought that. I was quite dumb but not anymore thanks to you. It also doesn't mean that I'll be getting some of those to turn on like at the Disco.

[@nicholashacking381]

I really am an annoying pedant: sorry - I cannot help myself. You said "frequency range" and wrote down wavelengths. There. That was cathartic, thank you. I do love the videos really.

[@bigclivedotcom]

I spotted that afterwards. But the two are related.

[@MiceliCreations]

I found a 40W :) My house smells great. Can't see but my house smells great. Herro?

[@chuckgoecke]

The vitamin D3 people get from UV exposure is very good for health. It doesn't take that much to get a good dose of the vitamin. I think around 15 minutes of getting most of your skin exposed probably gives you a good weeks worth of the vitamin D3 and it is a stored fat soluble vitamin. It takes a lot of weeks of no sun and no dietary D3 to become deficient if you started off with good levels. One thing I recall from my reptile keeping days, and in particular the AOL reptile keepers forum(we're talking about the mid-late 90's here) was that for the most needy reptiles, like a Green iguana and many turtles, you can't supplement their food with powdered vitamin D3 enough to prevent a deficiency. They have to get real sun or real UVb supplementation. I wonder if that isn't true of humans too. The supplements are probably okay, but may not get you all the way to optimal Vit D3 levels. People in cloudy cold climates, get every ray of sun you can in the winter, outside if possible, or get some tanning. On vit D and health, Vitamin D3 is very very important for much more than was previously thought, like bone health and calcium metabolism. It is very important in immunity and multiple other things. Getting adequate sun Vit D3 can have significant anti-cancer effects. A Harvard epidemiologist who studies the statistics of disease stated that for every one skin cancer death due too the sun, that same amount of sun prevented something like 20 deaths from other cancers. Bad ones, like colon, breast, etc. I think he dug those statistics from occupational comparisons(outdoor workers verse office workers and from people in southern climates versus cold northern climates The dangerous skin cancer, Melanoma, is not really very well coordinated with sun exposure. People get it all over there bodies, seemingly randomly, instead of sun exposed areas. The couple other more sun related skin cancers are all pretty minor, like warts. UV damages our skin my messing with the DNA, but not exactly like ionizing radiation, and creates molecular "bridges" (T-T and C-T)or kinks between specific base pairs. However, our cells have lots of DNA repair enzymes running all over out chromosomes fixing that damage, almost as fast as it occurs. When the damage happens faster than the fixers can keep up, that's a sun burn. I remember something my professor of Molecular Genetics told us about this UV damaged, beside the crazy high rate these damages occur in each cell(100's of time per min/per cell). He told us that the DNA repair enzymes that fix the specific UV damage are stimulated by visible light. Although trying not to be a doctor, with lots of caveats, he said that if you get a bad sunburn, like at the beach, of course get sun screen on as soon as possible, but that after lathered up with SPF 50, going back out into the sun might actually lessen the sun burn. I've tried it, and it works. Here an NIH article about UV DNA damage: www.ncbi.nlm.nih.gov/pmc/articles/PMC3010660/

[@phils4634]

There have been more than enough articles, all from reputable (i.e. peer-reviewed) sources clearly demonstrating the additional benefits of endogenous D3 vs. exogenous (i.e. dietary). Unfortunately here in Australia ("Dogmatism Central" for Planet Earth), "everyone knows" ANY sun exposure WILL cause "deadly skin cancers", so instead we have a population that hides from the sun, uses sun-block (VERY good at stopping D3 synthesis), and then we wonder why everyone's D3 deficient and / or osteopaenic! As Clive mentions - the workers who tend to get "skin cancers" (a convenient catch-all phrase here) are those who spend most time indoors; those who work outdoors are significantly under-represented, which supports the many studies indicating that the commonsense strategy of "little and often" is beneficial rather than harmful.

[@zwerko]

What do you mean under "UV damages our skin my messing with the DNA, but not exactly like ionizing radiation"? UVC for the most part and EUV entirely *is* ionizing radiation.

[@andipr1me43]

@bigclivedotcom: There actually are lights designed to emit UVB, or at least 70% of it compared to reptile lamps (which have 10% UVB at most). They are used for increasing trichome production on cannabis plants, as the UVB triggers some kind of defensive reaction which is normally only in found in plants that grow in higher altitude, as the atmosphere filters less UVB there. They don´t ship over to europe though, which is a shame. I would have a use for them ;) www.htgsupply.com/products/agromax-pure-uv-t5-bulb-4-foot Another use of specific UV-Wavelenghts is Photocemistry, where there are used as a reactive catalyst. But think a few kWs of highly specialized custom made LEDs for the price of a small country..

[@iRuf12]

yea Agromax T5 are currently ,the only way to produce enough UvB wattage/ Intensity to frost up the ganja , at least until the LED Industry make a 290nm diode that doesn't require a mortgage to purchase. Reptile/Parrot T5's do however make great propagation lights for weeds!

[@patsullivan9399]

You'd think the manufacturer would have some warnings on the package. Particularly because the UVC bulb fits the same fixtures.

[@listerdave1240]

@9:50 - about the black tubes vs the white ones for insect killers. I've been using UV insect zappers at home for the past thirty years or so. I would buy the black tubes for the bedroom because the others made too much light and disturbed sleep. However I eventually found out they were actually more effective for some reason or other. I noticed that with the white ones it was quite common for a mosquito to ignore it and keep buzzing around all night long whereas with the black ones it very rarely happens. I eventually started using only the black ones, even where the emitted light was not a problem though sometimes they are a bit difficult to find locally.

[@psirvent8]

Black tubes do still make everything white in the room glow a bright blue, hopefully it didn't disturb your sleep as much as the blue tubes did ?

[@listerdave1240]

@@psirvent8 Actually it isn't much of an issue, partly because I don;t have much that is UV fluorescent and even if there is a paper or perhaps a white shirt or something lying around it doesn't glow brightly and makes far less light than comes directly from the other type of tube. In fact even that glow itself is much less bright than for the lighter tubes. I don't think it is a matter of putting out less UV but possibly it is at a wavelength that is better at attracting mosquitoes while being less effective at causing fluorescence.