More fake germicidal lamps from China!

I've just made a video with a UV sensor that I think works OK relative to a £1000 UVC meter. https://youtu.be/7wibGVQpHCc

Big Clive

Can you send me a link?

Big Clive

I found uvc leds at digikey. All the devices that radiate in the high 200s nm had a forward voltage of 6.5 or 7 volts. Might be a good test to prove fakes.

Jeremy Impson

I just picked up a clone of a 200dollar snap on light and I must say the build quality seems to be pretty fantastic. I would love it see a tear down

https://www.ebay.com/itm/283830816852

Tommy Zaharakis

so with COVID19 crisis china takes a extra 3-4 weeks seemingling . I have been searching for personal sterilizers for healthcare workers @ work. Big Thanks to you BIG CLIVE for endeavouring to test them.. I am about to do my own tests with actual bacteral plates. In the meantime something came today that assured me of something small portable and has a old fashion glass fluorescent tube .

Tommy Zaharakis

Even the great orange man himself would like to pop a UV tube where the sun don't shine...

Search for USB UVC https://www.ebay.co.uk/itm/153905748947

Big Clive

saying that some visible light can kill bacteria... also, broan sales an exhaust fan that has purple lights on it that are supposed to kill bacteria. Idk if it works, but broan seems like a reputable company...

Michael Gilchrest

https://www.digitaltrends.com/home/blue-purple-light-kill-bacteria/

Michael Gilchrest

lets elevate the conversation. ITs actually a treatment. Not a smart of modern one. However certain types of light and lasers can benefit some conditions. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4783265/ We use certain UV light for dermatologic conditions. k

Tommy Zaharakis

Wow- thanks! I'm looking into building a germicidal enclosure box to treat PPE items for my employer (a small medical practice) since we are having difficulty getting any resupply. I've ordered a 'UVC' lamp (one of the 4-tube filament kind) but need to verify that it works.

Erik Erik

Thought you were kidding. Idiocracy is not a documentary 😭😭 I’m more scared of the people who look to him as a messiah. Everything he says means to annoy or marginalize someone. He has no credo but be the center of attention. If only he were charged war crimes on letting people die while his head was in the sand. That’s a great channel, Trump behind bars👻

Cerity

“So supposing we hit the body with a tremendous — whether it’s ultraviolet or just a very powerful light — and I think you said that hasn’t been checked because of the testing," Trump said, speaking to Bryan during the briefing. "And then I said supposing you brought the light inside the body, which you can do either through the skin or some other way and I think you said you’re going to test that too."

Dr. Obvious

Our "president" here in the states now wants to put UVC lights inside people's bodies lol along with just injecting liquid disinfectants... This makes me feel embarrassed to admit I live in the US... https://www.nbcnews.com/politics/donald-trump/trump-suggests-injection-disinfectant-beat-coronavirus-clean-lungs-n1191216

Dr. Obvious

Erik ERik here is a video of a guy who applied what you mentioned using UV sensitive beads... Seems that the fluoresce at specific wavelengths. I ordered them from Amazon and await arrival in 2 days. https://www.youtube.com/watch?v=q2FQZuEBNs0

Tommy Zaharakis

Since expensive test equipment is not attainable are there any practical, non-instrumental tests to see if a 'UVC' lamp really is UVC? Is there some chemical or material that will fluoresce only when the light shone on it is less than 300nm? Barring that, is there a particular plastic that is opaque to all light greater than 300? If so, you could put something mildewed under the plastic and see if the light kills it. You'd need the plastic to screen out the UVB though since iirc, that also kills mold and mildew.

Erik Erik

Does anyone have a link to the real one Clive has in this video that is rechargable with the quartz tube, please?

Simon Howroyd

I question the validity of the chinese spectra-photometers. I have seen UV and UVC diodes meant to measure UV but i am not as advanced electronically to build one like yourself. The spectra-photometers used iin undergrad were many thousands of dollars 20 years ago . I can imangine what they are now. I am going to make some agar plates with bacteria and test some of my cheap Chinese germicidal led lamps and my own known UVC lamps. I will link you the video when done.

Tommy Zaharakis

i have priced spectrophotomters, i have seen no solution below 500 dollars. There are pigments that fluoresce at specific UV wavlenghts and they can be used for Indirect measures. A chap on youtube did a video about 4 years ago using plastic 'disco beeds".

Tommy Zaharakis

It is possible that the seller is not the manufacturer and is just someone who has lower scruples and is trying for a quick profit.

I can see cheaper UVC LEDs at the online sellers like banggood and on eBay that look the real deal. But to indicate operation they use one or more visible LEDs. But how do you know that the main UVC LED hasn't degraded in performance to the point it is not doing its job. I guess it would require a sensor capable of detecting UVC wavelengths and a suitable filter in front to narrow it down.

Big Clive

Most viruses are disrupted by absorbing radiation at or around 265nm - mercury discharge lights' peak emission of 254nm, while not optimal, still delivers a lot of energy at 265nm. The latest UVC LEDs peak radiate between 260-270nm making them ideal for the task - but as Clive pointed, out, are very expensive. Blue/purple UV LEDS which peak at 405nm technically could produce *some* energy at shorter wavelengths - the curve tails off in both directions - but the level of emission below 280nm is extremely low - anything that is produced gets absorbed by the plastic housing. And the disinfection curve also allows for some effect at longer wavelengths, but again, at a negligible level. To advertise disco LEDs as disinfecting is like shaking the washing-up basin while you're doing the dishes to leverage the "ultrasonic cleaning" effect ;-)

Gordo

So you would think.. In the same way, the risk of someone choosing to light an art exhibit with UVC tubes would be low, but....

Gordo

as in my prior comments its possible it still can be germicidal without producing ozone and damage. Bulbs have a wider spectrum into the region that makes ozone ( 180's nm region) i get your theory. I am not sure its a 100% endicment of these ebay items. I will let you know on my agar plate tests on bacteria

Tommy Zaharakis

Hi Clive, We did some work recently on a UVC sterilisation project using LEDs. As far as I know there are only 2 manufacturers that have UV-C LEDs in production and they are very expensive (one manufacturer was £35 an LED with a qty of 1000000 devices, the other was £15). Neither LED performs very well and only last a little over 500 hours as the UVC destroys the LED.

so here is data that wavelengths above 270 leds work https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4702654/ . I have tried to find a direct spectrophotometer to measure germicidal effect. I am going to do direct studies with agar plates.

Tommy Zaharakis

Surely the risk of someone using this by mistake is low? I mean honestly the first thing you do when you buy one of these is stick your hand in front of it to see if you can smell the famous "burnt pork" smell from Clive's first UVC video, right...??

Berkeloid

This has already happened to me. If you leave them negative feedback (which I do when they make it hard to get a refund) then they block you. It's interesting how after one seller blocks you, suddenly there are a dozen sellers you can't buy from - i.e. each seller has a bunch of different accounts (against eBay policy but of course eBay don't care). So I figured well two can play that game, now I'm up to my third eBay account...

Berkeloid

Big Clive, poking the ants nest. :)

Wim

I can see a time when certain eBay sellers just won't post either to you personally or the IOM. If ever that happens I'll gladly have them delivered to my address to forward on to you.

Neil Tonks

That probably explains why these standard mechanic's work lights were originally adapted to be near-UV. I think many Chinese sellers are just cashing in on lack of knowledge about the different types of UV.

Big Clive

I like how honest they were that the printed COB work lamp on the circuit board :D

John Carr

A ultraviolet light can be found in every mechanic shop. I use one from time to time to find leaking injectors under the valve cover after dying the fuel with florescent dye and A/C systems also have dye in them for small leak finding

Coil B

I think Clive is secretly planning either a collaboraton with PNAU or he's planning on making his own video. Hair, makeup and all...

The same mentality that caused the baby formula scandal probably