The green banana test.

The efficiency of the UVC LEDs is much lower than traditional mercury tubes, but they do at least work. I'm not convinced that the implied quick-wave is going to actually sanitise much though.

Big Clive

Inspired by recent videos I got a 20 euro "mini killer uvc" led light from ebay and tested it on a banana. It did actually pass the test but took a good bit longer. With not much to see after 15 minutes I left it an another hour and by then it had a very noticeable bronze stripe. The light is thumb size dongle thing that plugs into your phone and has a single led chip. Claimed output is 1w. You're supposed to use it disinfect buttons and door handles going by the ebay pictures. I would wonder how long you'd need to expose something for it to have an effect give it's low power output. Still it's an interesting little thing.

Denis Looby

On the banana that got baked by the UV-C lamp, you can even see faint discoloration on the far edges away from the middle. I seem to recall from your video about that 23497324 LED blue lamp that you mentioned that one got rather hot.

Roland Roberts

This is why you have to read the fine print when buying one of these devices - if the product "can kill bacteria" then they could send you a UV-A light without it being false advertising, but since most of them claim it "kills 100% of bacteria" then you are within your rights to return a UV-A device.

Berkeloid

Did you see this? https://store.auvhealthcare.com/10-pack-uvc-tab-photochromic-uvc-measurement-cards-food-beverage/

Bill Kerr

The Wikipedia entry for Light Emitting Diodes suggests that even UVA LEDs may have some useful antibacterial properties. There's a link to a research paper, but you have to pay to read more than just the summary. https://link.springer.com/article/10.1007/s11517-007-0263-1

Gary Bleads

"a simple refutation for flat-earthers" - no such thing. Unlike (most) scientists, reasoned argument doesn't tend to work against flat-earthers and conspiracy theorists. They always find some way out - even if it's scientifically impossible.

Mark Gray

Well done sir that was awesome!

PeteyPak

excellent! now you can send the video to the seller who afirm the garbage disco light is UVC! because no expensive tool is needed and the result is right here...

Groovy1024

You've now shown two ways to brown your banana, heat and UVC. Perhaps testing lamps against real bacteria, say yeast, would be more representative? It's not that I believe the fakes are UVC - it's just an interesting exercise in constructing a convincing proof, like trying to find a simple refutation for flat-earthers.

Short and sharp and to the point! Nifty.

We could use the circuit board masks and UVC lamps and put some finely detailed designs on them.

Nani Isobel

Stop confusing us with reasonable and important details! I guess it's possible someone might confuse UVB and UVC illumination of any type, LED or tube. But I don't expect the scammers to go beyond the cosmetic "make it purple!"

Nani Isobel

Time to UV some rude words onto a banana.

mj

Thanks for that Clive. I'm going to test my disinfecting box (supposedly with UVC LEDs) using the tape on banana trick.

Does UVB blacken bananas? Sorry to keep banging on about it, but if you *require* UVC, you need a clear test.

Mike Page

top banana

Come, mister UV man...

Michael Thompson

Just wait a Daaaaaaaayo!

Michael Thompson

One banana, two banana, three banana, four Wait, not enough banana!

Mark Gray

I approve of The Old Green Banana Test.

Matt Tester

Nice! Now people know an inexpensive way to test if their lamp is real.

Nani Isobel

so glad you did this. It may help people. I messaged way back after i found it in a video from years ago. Since then many others including a vendor has used it. Saved me from having to buy an expensive UVC meter.

Tommy Zaharakis

I wonder if the UV killed the fruit fly larva that is in the peel of the banana that had the real UVC exposure.

Charles Bruckner

Your fingers look like you've been working in the garden, but somehow I don't see you as a gardener... :-)

Paul Schuur

I don't know if I'm sad or glad that Clive did not try to pass the banana test.

Simon Mikkelsen

YouTube sensation Bigclive sparks worldwide green banana shortage

Neil Tonks

That's bananas

The Tinkering Shed

Green bananas. Its no Green Onions, but you can still dance to it.

Michael Thompson