I'm not sure how widely these were available before the pandemic, but they're now all over eBay due to the market that was created for testing germicidal wands and lights.
One very useful function of these it to test the ability of materials to block UVC light. By placing the test material (like my glasses) between the UVC source and the sensing surface it will indicate if the UVC is blocked. In my case all my glasses blocked UVC, which is reassuring.
The UVA test surface seems to respond right down to the near-UV LEDs in the 395-405nm range.
To find these on eBay use the keywords - UVC test card.
Price should be around 5 £$€ for a pack of 5 and not much more for a pack of 10.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators
One very useful function of these it to test the ability of materials to block UVC light. By placing the test material (like my glasses) between the UVC source and the sensing surface it will indicate if the UVC is blocked. In my case all my glasses blocked UVC, which is reassuring.
The UVA test surface seems to respond right down to the near-UV LEDs in the 395-405nm range.
To find these on eBay use the keywords - UVC test card.
Price should be around 5 £$€ for a pack of 5 and not much more for a pack of 10.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators
This rather interesting little card is a UV test card courtesy of the Pandemic. It's widely available on eBay now, and it's very interesting because it has two zones. one detects UVA or thereabouts and the other detects UVC and it uses two completely different techniques to test that. now.
I Do have a UVC button here and a near UVA button here. So I'm going to set this up so we can take a closer look at it one moment. please. That's better.
So the first test I'm going to do is with this Automotive leak tracing light for using Tracer dies and if I put it near both these areas, you'll see that the one with the UV test area, not the UVC. it changes color and when I take it away, it stays in that state and it will gradually reset back to transparent again. But when you bring the UV near it, it goes very decisively dark. The UVC is different.
It's using a phosphor, so I'm going to have to turn the lights off for this and set this up one moment. Please pitch black this time. but as I bring the UVC light up, it makes the UVC section fluoresce that is a phosphor much like you might find inside a fluorescent tube. It should also, let's just cut out and it's safety here.
It should also actually make the darker UV go as well because this is a mercury vapor lamp and it will be putting out both those wavelengths. Okay, watch your eyes. the light is about to come back. The light is back.
So pretty. Neat little cards. Very simple. Well Am I See, they're very simple.
They're not that simple. They've always put a bit of research into it, but these things are now widely available on eBay in packs of five or indeed, packs of 10. it doesn't really cost that much difference to go for the higher number. and these things were a price gouged a bit during the pandemic, But now that, well, now the media has lost interest in the pandemic and the demand has gone down, the price of these has lowered dramatically to the point that I decided to get through them just as a precaution.
But I shall put links to below. put a search link to eBay so you can find these uh, if you want to do these tests yourself. But interesting thing, a UVC and UVA test card.
And there is me watching with covid lol
Very informative video clive
This is off topic and will probably sound ridiculous, but this morning I had an idea pop into my head and now I am curious to know how you would go about building one or if it’s even possible: a thermistor controlled outdoor thermometer that displays a different colored led depending on the temperature outdoors, for example; a red led for hot temperature, green for mild/cool, and a white led for cold like ice or snow? (Edit: this would be used as a novelty item). I love your channel, btw. The amount of knowledge and skill you have amazes me. Thank you for sharing your talent and humor!
Is it just me, or is requiring you to LOOK AT the UVC light to identify it as UVC a pretty significant design limitation? You can shine the UV while looking away, and then check, but not for the more harmful light…
Dumb question. Does this test work the same way as these fancy UV set resins that never work properly for me?
Kinda weird that the test card for UVC doesn't persist like UVA. I would have assumed it to be the other way around since it isn't recommended to be near UVC sources.
I believe typical window glass blocks out most of UVB and very little UVA. Assuming the "UV Test" portion reacts to UVA and UVB, it might then be possible to qualitatively evaluate each separately by first placing a small piece of glass over the UV Test patch, exposing that to see if it changes color, and then removing it and repeating the test. We know direct sunlight contains both, and probably the automotive diagnostic light mostly or entirely UVA. So one would have a "known", or at least "supposed" source to use.
Great channel! But can you talk like a normal human?
So many unanswered question after watching your 50% analysis = follow-up question that are never answered. In Australia we would do it 100%!
Moist
cheers Clive, those are really useful 🙂
UVC LED technology has grown leaps and bounds the last few years thanks to the pandemic. Alot of them have a blue visible glow along with the UVC and in the same guy package… As a safety feature so that it indicates the lamp is on. Sometimes there are 400 nanometer near UV sometimes they're 365 nanometer and sometimes even deeper. But still usually in the visible range
Some manufacturers actually use phosphors along with the UVC die package… A little bit of built-in safety and keeps it visible even though it does reduce the power or beam path a bit
What use are they?
Reminds me of the couple IR test cards we had in the shop back in the early 90's for testing consumer remotes. Fast forward to over a decade later, and I impressed the owner of an EADL(Electronic aides for the disabled) business with my knowledge of checking an IR remote with a phone camera that I got hired and basically became the lead engineer for about 13 years. Funny how odd bits of knowledge can affect one's life!
Cool. Keep working. Good luck! 👍