While I like test equipment, I don't think I could justify spending £1000 on a UVC meter to test a £16 eBay disco light.
Instead I settled on an Adafruit UV sensing module with onboard amplifier, and a piece of glass.
I'd say the results are fairly decisive based on a conclusion extrapolated from current LED construction technology, visually perceivable wavelengths and the UV transmission of standard glass.
In short. Many of the eBay "germicidal" lamps are a rather cynical scam, especially in the current global situation.
But hey... We don't call eBay China's dumpster for nothing, and to be fair, it does make dangerous stuff available to the technically adventurous that simply wouldn't be available from "normal" shops.
Here's a link to the UK source of the Adafruit module.
https://www.ebay.co.uk/itm/232427124316
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 advertising algorithms allowing it to be a bit more dangerous and naughty.

15 thoughts on “Testing uvc lamps with a cheap uva/uvb sensor.”
  1. Avataaar/Circle Created with python_avatars l p says:

    If we put 3 sensors side by side, with
    A) no filter
    B) glass filter
    C) magic filter
    then use an A/D circuit of some mcu to read off the measured output of the sensors,
    we could come up with a meter to tell whether there is UVA/UVB/UVC.

    I just wonder what is the best filter for C). Could it be some glass, quartz, plastics etc?

  2. Avataaar/Circle Created with python_avatars Richard L says:

    Use the piece of glass to shield your eyes while testing your glasses.

  3. Avataaar/Circle Created with python_avatars Charles Lambert says:

    I wonder if a low tech way would be to see if a few days of constant exposure of a plant such as cress to the 'uvc' light kills it.

  4. Avataaar/Circle Created with python_avatars John Clulow says:

    I believe window glass will block both UVC and UVB ranges and have little effect upon UVA.

  5. Avataaar/Circle Created with python_avatars Fity Bux says:

    You can get UVA / UVB / UVC meters now for around $150 to $250 each. (And each one will have a peak sensitivity in those ranges.) If you want to make a fancy color spectrum graph, you need thousands of dollars of lab tools.

  6. Avataaar/Circle Created with python_avatars Rolf Mears says:

    The detector chip used has a specific UV-C chip in the same family. You could get one and try swapping over 🙂

  7. Avataaar/Circle Created with python_avatars Bobby Benedicto says:

    Hi Clive good day. Would it be possible for you to show me how to connect the sensor to multimeter and power? thanks

  8. Avataaar/Circle Created with python_avatars INNOVATION & INITIATIVE Diy says:

    I heard by Derek Muller in his one of video that all Ccd sensor are uv sensitive but the glass lense used in it block the most of uv light but I wondering if we use parabolic lense to focus on Ccd it will also pick up light so easily ..
    So can you do my thought experiment in reality ?if it's possible to turn normal camera into uv sensitive .

  9. Avataaar/Circle Created with python_avatars INNOVATION & INITIATIVE Diy says:

    I thought the phosper used in white led will glow much brighter in uv c Mercury lamp similarly some other glowing plastic which glow very bright in blue and led uv light but don't know why it's not glowing better in Mercury uv c lamp ?
    And also … I used car Halogen lamp and sunlight with lense as uv source to cure
    uv solder mask both uv source cure it in just 10 to 20 second of exposer but when I tried same with this uv c Mucuery lamb hopping it will be good and rich source of uv c it will cure mask even faster but not it is not as effective as sunlight and car Halogen !! Why are type c lamp is fake ?

  10. Avataaar/Circle Created with python_avatars Techcafe says:

    if an ordinary piece of glass blocks UV light, then what type of glass is being used for that UV lamp in the lovely pink lamp holder?

  11. Avataaar/Circle Created with python_avatars Hola! Yo.C says:

    I like the idea of using the glass as filter but I read that glass filter both UVB UVC .. so can we conclude from test that the light might emit only UVB hence maybe it's not UVC

  12. Avataaar/Circle Created with python_avatars Interpleb says:

    I just don't get this video… Per the Adafruit 1918 Analog UV Light Sensor docs: "covers UVB and most of UVA spectrum" yet you say the mechanics light is not true UVA… Its more likely UVC or least of UVA and cant be UVB.

  13. Avataaar/Circle Created with python_avatars Foogod says:

    It occurs to me you could probably make a pretty good UVC tester by using two of these modules, one bare and one covered by glass, and then feed them into a op-amp/comparator to output the difference of the two signals. (though I'd bet you could probably look around for a fairly cheap UVC pass filter to put in front of it too)

  14. Avataaar/Circle Created with python_avatars jparryprodeal says:

    Hi what is the glass you are using, normal or special glass , how it can black UVC light. Thkx

  15. Avataaar/Circle Created with python_avatars Fahrul Rizal says:

    Coba dong uvc

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