Mary's calling my bluff...

I've got one on order from Adafruit as a module with integrated amplifier.

Big Clive

I found a sensor that's uv sensitive GUVA-S12SD which is available on breakout boards and can be used with an arduino to measure UV intensity. Also found a site describing how this device, modified with tweaking the breakout board to better amplify the uvc specific wavelengths, is being used in an interesting project. https://hackaday.com/2020/03/27/measuring-uv-c-for-about-5/

I'd threaten to open a complaint on Ebay and to leave a bad review for the product and for the seller. It's not your job to prove that the product is a scam, it's her job to prove that it isn't.

Amazon has this UVC-specific tester for around $105 US, although it won't ship until around the middle of June: https://www.amazon.com/dp/B087LRJTQB/ref=sr_1_61?dchild=1&qid=1587786891&s=industrial&sr=1-61

She is also taking the "i'm only the middle man" approach which is equally as frustrating.

If that was ever tested at all (i.e. not pseudoscience) then it will have been tested against UV-A and UV-B, not UV-C. Almost all of the latter is absorbed by our atmosphere (just as well really - for us!)

Mark Gray

https://www.amazon.co.uk/SmartSun-UV-Wrist-Band-Indicator/dp/B00JYBR6U8

evilution

Personality Clive I would call her Bluff. The next time you are are in Glasgow contact the university as I am sure they will have have the test equipment that you need. Get them to produce a nice lovely report for the lovely Mary and you can send it back to her, include detailed instructions on where to insert it. I am sure that the university will be delighted to help you when you offer a nice plug on your YouTube channel.

And if anyone could build a spectrometer, you could. There are even a few spectrometer build guides on YouTube - whether or not they work is a different question, of course, but could make an interesting experiment. This is the first one I got in the search results: https://youtu.be/MgogwcXUIoc

I believe Big Clive!

Richard Boyce

Digikey has UVC sensors for a few dollars such as this one: http://www.geni-uv.com/download/products/GUVC-S10GD.pdf Digikey PN: 2096-GUVC-S10GDCT-ND USD 8.78 in single quantities. It is sensitive from 220 to 280 nm. These are made for sterilization lamp monitoring.

Seat Warmer

I thought I saw you test the wavelength with the back of your hand. No burn, no UVC!

Would this work? https://www.newport.com/f/ultraviolet-uv-sensor-cards

This is the time to reach out to the community. I reached out to one of my local stores that specialize in LEDs. they have a spectrometer, but it only goes down to 350nm.. I will try my luck next at a university i used to study at.

Niklas Haglund

I wonder if the seller is just cutting and pasting a description from whatever manufacturer actually produced the thing.

Paul Ste. Marie

Just make up a movie quality dummy box with dials and flashing lights and use that... its not like they'll know the difference! :)

Nub

Is there a university on the Isle of Man? If they have a physics or chemistry department they probably have a spectrometer.

Yes clearly she didn't realize you used your "B.S." tester.

Maybe we should crowdfund getting Mr C a photospectrometer?

A saxaphone is an instrument

Gordo

...or I could point the spectrometer at the purple part of my screen while playing your teardown video - I'll bet there would be no UVC detected.. PROOF!!!

Gordo

Clive, I've a photospectrometer - if you send me the panel with the LEDs I'll test it for you..

Gordo

Would UV-C discolour meat quicker than just oxidation? That might be a quicker test, get some meat product and expose it to UV-C Vs non UV-C?

Marmite

No, that would be Carry On Sergeant (1958).

Does that work with the new plastic £20? The one shown on their web-site is the old one.

So will "my system tells me that you're a wanker and so is the misadvertised unit you sold me" do. It was nicer (if only slightly so).

Why not make a "tester". You are an experienced prop maker so making something that gives a readout......it doesn't have to be real, just enough to fool them.

John Carr

Mary had a little scam, little scam, Little Scam. Mary had a little scam whose UVA was shown.

Have you considered building something like this: https://youtu.be/MgogwcXUIoc

That’s a quick turnaround from “it’s purple, isn’t it?”

papercrane, The Cuddledemon

Clive a true test of UV. Is it possible that you can create bread mold and a test it for 12 to 24 hours to show which is real and which is fake?

Looks like the Snap On tools light except white. Im sure the Snap On light is like £100+VAT!!

+1 for Matthias Seifert's idea. Keep it up and don't let "Mary" grind you down.

Shaun Runham

If it smells like bacon, your light is putting out UVC. If it doesn’t, it isn’t. I’d do the bacteria thing someone else suggested above, video it, that’s probably a good demo

Shira Wolven

You could probably do a fairly convincing test with https://en.wikipedia.org/wiki/Photochromic_lens

Peter Eduard

Why do you need to prove this ? IMHO you already did so. Let her barf up the proof.

They are the ones making the claim, not you. They have to be the ones to back up the claim. https://yourlogicalfallacyis.com/burden-of-proof

Nani Isobel

Doesn’t surprise me. I’ve had similar problems with eBay sellers and fakes. If you want your money back then eBay rules tend to be weighted in favour of the buyer. If not and you feel like playing the game then fighting fake with fake sounds good to me. PS - can use a CD as a crude diffraction grating for visible light but that wouldn’t work for UV-c.

Mark Gray

Use a graph from Wikipedia or surveying that shows UVA vs UVC spectra

fluffy

I was going to suggest the same as Matthias. Pop your multimeter into a box with the display exposed then rig up a photodiode or similar which causes the meter to display 395 when you shine the light on it. Send "Mary" a video of you doing that.

Perhaps the purple LED would be more convincing..

I second the diffraction grating and photo cell/resistor idea. Edit: Obligatory relevant Thought Emporium build: https://www.youtube.com/watch?v=pIk8I10ZmYY

Andreas Schuderer

You could build a fake UV-wavelength-detector. Just complex looking box displaying the "wavelength" triggered by a hidden switch. Answering with a fake wavelength detector to a fake lamp.

Culture some bacteria on an agar plate and do a test with a real UV bulb. Expose half to real and half to fake UV.

The Griffiths Family

Did they pay for return shipping because it was their error❓

Cerity

Yes mobbing for a purpose is fun. Being on the other side isn’t. And it’s not Mary’s fault most people are sheep

Cerity

I've had similar issues with these foreign sellers based in the UK on eBay and Amazon . I bought a couple of hand torch LED bulbs from eBay advertised as being dual polarity - I needed the +ve connection on the tip. When they arrived they weren't dual polarity and would only work with the -ve on the tip. I spent weeks going back and forwards with them wanting photographs, detailed technical explanations, my shoe size, delays while they contacted the mfg in China etc. In the end eBay allowed me to return them for credit. I thought all the hassle was because they didn't understand what I was saying but no it was just to make me give up and not return them. Mary is just playing a game.

John Russell

Thunderf00t has access to the right equipment to test it

God 420

Just make a box with "UV tester" written on it in crayon and a red fail led.

"Big Clive" - yes i have a video demonstration showing it is fake full refund or i contact PatPal

God 420

I am sure at least one of your followers has access to the right equipment.

09Klr650

The problem is whether the diffraction grating will transmit UVC. But you could test that with a tube lamp.

adrian

In principle, it's a narrow entry slit, a diffraction grating, and a photocell that can be placed in the appropriate position. A simple screen is sufficient for visible light but obviously won't worek for UV.

adrian

Try killing some germs with it - petri dish, dirty finger etc.

adrian

I'd be happy to stare at that thing for an extended time but I doubt that would prove anything to "Mary". I'm curious if Mary knows who she's talking with? Send it to that Applied Science guy! edit: I see I'm not the first, carry on.

Aaron Nadler

Could you not use a £20 note to test the UV lamp? https://glowtec.co.uk/how-to-test-a-blacklight/

Time to invoke #followerpower :)

Cheetah Spottycat

If I'm not mistaken, this will prove the fake does prouce light outside of the UV wavelengths, but won't prove it doesn't emit UV wavelengths The other way - finding something to filter out the visible light and record the UV would work

Adam Pátek

Sure, that builds Clives eventual case, but will eBay UK even care⁉️

Cerity

https://www.ted.com/talks/james_veitch_this_is_what_happens_when_you_reply_to_spam_email/ Unlike the TED from James Veitch which had no actual goods, I’m pretty sure it’s like in the US, the onus is on the seller with data sheet if it wasn’t already supplied

Cerity

Nice! I was just looking at this : https://youtu.be/desLn3tMLcc

CattusExMachina

Simple, effective and cheap. I like it! Certainly grounds for "having suspicions that the goods are not as described", I'd say. Move the onus onto the seller to prove that the goods are certified as described. Despite the nature of Clive's channel, he's under no obligation to comply with her request, whereas she has a legal responsibility to respond to his queries, I suspect.

Does UVC even pass through the plastic lenses? You could expose something reactive, masked by the lenses, to a real UVC source.

Andy Brown

That's interesting. I've just ordered a similar module by Adfafruit that will give a simple voltage based on UVC spectrum.

Big Clive

eBay should do a lot more about fraud. There is also a lot of stuff that claims to be "in your region" currently and after you buy it, it ships from china. ...and a lot of similar stuff. Even if you open an issue and it's clearly the sellers problem, eBay sometimes refuses to help.

just_noXi

One of these? https://hackerfarm.jp/2020/03/nukemeter/

I lied, was thinking of Andreas Speiss https://youtu.be/sttQAL4r4TQ

Simon Howroyd

I'm pretty sure Thunderfoot will have access to something

Send it over to Julian, I think he had a wavelength measuring thingy that he made?

Simon Howroyd

What a horrible artificial narrator voiceover that video has!

Frank

Grab a likely data sheet for the LEDs. They'll say that is not the LED they use, ask them for the part number/data sheet in return.

Maybe contact the UK Consumers Association (Which) they claim to be concerned with this type of 'fraud' and many of their readers could well be 'taken in' by these fraudulent claims. The problem with some of the proposed solutions is that anything that involves glass will almost certainly skew the results due to the effect of the glass. Also look at https://hackaday.com/2020/03/27/measuring-uv-c-for-about-5/ might work but Mary would probably claim it's not 'calibrated'.

Mr B Shepherd

I used a simple diffraction grating as suggested to differentiate light sources for colour photography BITD. It works very well with discrete bar spectra as they are well differentiated. It is less successful if lamps have a phosphor coating as that tends to swamp the visibility of the bars

Test with £20 note: https://glowtec.co.uk/how-to-test-a-blacklight/

Robert Sanges

Show her a random test device and tell her yes indeed my system tells me that you're a wanker and so is this crap unit you sold me... but nicer.

Michael Thompson

It'll come under the Consumer Rights Act (formerly Sales of Goods act) via eBay. As you've had it less than 6 months, it's for them to prove it works, not you to prove it doesn't work. The onus is on them to prove it is functional and fit for purpose.

Bigclive, do you happen to have a diffraction grating slide? You can make your own spectrometer on the cheap! https://www.instructables.com/id/Spectrometer-phablabs/ (There are many other ways of doing it, but this one should suffice:-)

Bo Holbo Rasmussen

Reach out to Applied Science for one *very* awesome crossover video.

PeteyPak

You can go DIY with relatively simple tools and low cost (eg https://www.youtube.com/watch?v=pIk8I10ZmYY) or get pre-built one fot <200GBP (eg. https://www.ebay.co.uk/itm/Light-Spectrometer-UV-IR-for-USB-connection-to-Windows-PC-Pro-Bundle/202673323950)

JD

depending on how much you want to get into this, something like a GUVC-S10GD which would work as a photodiode just for the 220-280nm UV range.

"I need the UV LEDs for the sterilizations." "You mean UV-C or the purple ones?" "What's the difference?" "Well, the UV-C are 8 times the price and will take 2 months to get there." "2 months and at 8 times the price! We can't do that, send the purple ones." Aaaaand Scene!

In high school, I made a spectrometer by taping a prismatic slide (obtainable at my local science museum - or many Chinese supply houses) that would split a light beam into the colors onto the lens of a Polaroid camera. I then clamped a meter stick and a test tube clamp to a bar set in my high school's science table, which had bushings for that sort of thing. We had a bunch of sealed, low-pressure, single gas glass tubes suitable for putting into a lamp. We also had a small tesla coil in a hand-held plastic case. I'd clamp the tube and the tesla coil so they touched. I then killed the overhead lights, turned on the tesla coil and opened the shutter. When the photo developed, I had light bars either side of the (over-exposed) glass tube, with a meter stick as a gradient. I got the distance (with much patience and many exposures) right so the mm on the meter stick showed the nm of the spectrum. Even without that you could scale the gradations. My science teacher then used the photos in tests for the students to determine the gas in the tube. You could probably do a setup like that using a phone camera these days and prove the bit..er..lady wrong.

Mike Bird

Ordinary fluorescent bulb phosphors will fluoresce in UVC but not UVA, so if you have a broken fluorescent (or compact fluorescent) tube, you can use that as a UVC sensor.

John Rehwinkel

Take side by side photos 9f a real one and the fake. Then find a filter that turns the real one "invisible" (maybe a lighting gel) but still allows the fake to be visible. The other way around would also work. This would prove that the fake does not output the same spectra Do it all in real time on a video and send her the link

GL_1_Code1_1A

I’ve definitely come across many eBay sellers that really have no clue what they’re selling and they’re being scammed by their supplier or just copy pasting from other listings, but this one knows what a wavelength is which makes me think they know what’s going on. My recommendation is to find a screenshot of some spectrometer software with a 405nm LED spectrum on it, put it on your computer screen and then take a picture of it with the light next to it. It’s not worth their time to forensically analyse an image or debate with someone who clearly knows the ruse.

WizardTim

I have a trombone you can borrow.

http://www.geni-uv.com/download/products/GUVC-S10GD.pdf - 220nm to 280nm UV-C sensor. Digikey has them for about $9. https://www.digikey.com/product-detail/en/genicom-co-ltd/GUVC-S10GD/2096-GUVC-S10GDCT-ND/10475469 There are a variety of UV spectrum sensors available from DigiKey. Building an instrument might be possible? https://www.digikey.com/products/en?dc=87531

Why don’t we all buy one and then open cases on eBay. That should spoil Mary’s day and make her think twice about arguing with Clive in future.

How about using this method? https://youtu.be/G_Fsp7fzNYI

Frankfactor

“Well Mary the fact that it hasn’t cooked my hand or my eyeballs suggests this isn’t any kind of UV. There is no lingering smell of roast pork with a subtle hint of ozone. How ever my pet hamster is having a whale of a time in his new rave cave. So this item is fake.”

I agree with Russell that it's probably the supplier that's conned the seller. Especially with these shops that sell a load of different things, they almost certainly don't perform their own checks. Would be good if someone could lend you a spectrum analyser though, that would make interesting viewing if nothing else.

Dan Craggs

Send a video of you staring into it for a full minute with unprotected eyes. :)

Nothing a prism and some of your flouresant powder could not solve 🤣

Graham Eida

"Did you test its wavelength with an instrument?" Well, the instrument is not specified. Feel free to use kitchen scales and a thermometer to measure the wavelength.

Michael Vokabre

Disagree strongly with the “give up it’s too hard” option, this the time to make a stand! Surely between the patrons we can work out a way to win in this case, it’s so blatant, and the possible damage this could do is just too much to walk away from I for one am willing to put my money where my.....keyboard is. To angry to think constructively right now but come on guys. Not going away Thats what their relying on!

Surely that special UVC death beam filter you used on the masking film covers it.

Sounds like a "fund raiser" stream is needed for essential equipment.

it is highly likely this person doesn't actually know what they are selling is a bluff - and is doing what they are told to do when dealing with complaints from 'warehouse items'. all she's really asking for is 'concrete proof' that can be sent up the chain to someone else to deal with

Russell Peake

Yes, turn it around, ask her to supply information.

You do have an instrument, your skin did not burn nor your eyes pop.

I mean you Do have such a tester. It's called the back of your hand, and from what I understand it's a pretty definitive test. I saw a guy do that in a YouTube video once. :). I had a similar problem with an eBay seller a while ago when they kept claiming that in order to prove they hadn't shipped my package I needed to go to my local post office and have them start a test Trace. But the trick that saved me was that their queue depth on these prewritten replies isn't all that deep. Get them far enough off script with some bullshit of your own and they'll do something dumb like reuse one of their copy/paste redponses At which point you can turn to eBay and say they are acting in bad faith and not participating in the resolution process. If the eBay seller has got to pick the test you you could use, everyone would be asking for Tunnelling electron microscope and chromagraph results.

Ken Kopin

depending upon how much time you want to put in with this, you could set up an experiment to show it two pieces of food or agar solution, one exposed to the lamp and one not, and see what level of rot they have.

Pittsburgh Flip

I'm having the same issue with one I bought. The seller doesn't list wavelength info in the description, so I've asked them to send the data sheet from the supplier

The Nitroglycerin Child

Some people just won't be argued with.

Tell her to give data sheet lab test about its output wavelength and power

Nguyen Quang Minh

Keep on it, they will get tired and send a refund

Mike

Lol, you must be a bit bored to bother arguing with ‘mary’. Keep up the great work

Adam Pepper

Well you tried. Add it to your list from Santa

Neil Tonks