2nd Gen QuantaDose® Reusable UVC Light Test Card with UV Intensity Strip Sensitive to UVA/UVB/UVC Light

I got this to determine if sunglasses (and other eyewear) actually delivers purported UV protection. The card works great. I merely covered the UV sensitive areas with the lens, and exposed it to sunlight. Quickly remove the sunglasses and check if the area is still white. You have to be quick, because the ambient UV light will affect the sensitive rectangular spaces.I am happy to report that the glasses I tested did indeed have UV protection. Even a pair of reading glasses offered UV protection. (The lens doesn't have to have dark tint to possess UV protection.)I wish the card came with a case/sheath, for protection. Otherwise, it functions exactly as expected. Great assessment tool. 4.75+ stars with a very high level recommendation.

Very Good!

The little experience I have with these reusable card UV detectors, this one works best for UV-A.It fades fast, but registers better than the other QuantaDose reusable card in the photo. Both luminesce under the UV light, but only this one retains it for a few seconds after the UV is shut off.

Great item highly recommend

What I liked about the card is how easy it is to use, that it's sturdy and small (like a store or credit card), and easy to take along on a walk. I initially used it to test different articles of clothing, hats and sun umbrellas to see if they blocked or reduced UV exposure, especially those not UPF rated. I noticed the color displays quickly uncovered, then takes a few seconds to reset to get a new reading when covered. I was please to find many non-rated fabrics provided protection. Watching the videos explaining the use of the card made it easy to use the card when it arrived.

Good

This is good for detecting the presence of UV-C using the green fluorescent dye, but the purple photochromatic area responds to 320-400nm UVA/UVB (not UV-C) which your light source may not emit much of at all.Testing this with Philips TUV 4W FAM 4W (G4 T5) tubes, which are advertised to emit almost entirely 253.7nm UV-C, and only about 8% in the 320-400nm UVA/UVB reaction range of the purple dye, all according to the Phillips spec sheet, I get almost no reaction from the purple dye.The purple photochromatic dye obviously works in the 320-400nm UVA/UVB range though because I get a very dramatic immediate reaction in direct sunlight.So my conclusion is that this will tell you that you have UV-C, but it won't help you quantify the intensity of it. Thus light sources that are perfectly fine will appear to "fail" simply because their spectral power distribution curve is too narrowly spiked in the UV-C range and not wide enough to also produce a large enough amount of UV-A and UV-B.The only way to really test germicidal lamps though is with bacterial cultures because the germicidal function is not just the intensity of the light source, but also the exposure time and the "penetration" of the light into cavities on UV-C opaque surfaces, the amount of light reflected off of the inside of reflective boxes that actually reaches a surface, and other complicated real-world factors.That's the main problem with UV-C disinfection at the moment. A lot more testing is needed to determine what sort of sanitizer box/cabinet designs work and how well.

Without knowing it, back in 2020, I had purchased a counterfiet UVC germicidal corn-cob LED bulb here on Amazon for $75. I used it for ~2 years thinking it was disinfecting masks, gloves and the occasional hotel room. Turns out it produces no UV light whatsoever and the only way I could have known that is with a product like this. It also turns out there is no shortage of flim-flam people out there willing to knowingly sell garbage but lie about its features and exploit people to make a buck.As an aside, in general, if you are in the US, I would NOT PURCHASE any germicidal UV light product here on Amazon. Amazon does not expend the resources necessary to prevent sellers from duping its customers with fakes. The Quantadose tool is an essential tool to help customers know if they are being duped.The UVC germicidal lamp product I ultimately found here in the US and liked is the "Cleanaire 15 in. Portable UV-C Disinfecting Work Light with Motion Sensors Adjustable Timer Alert Warning Function" which I found at HomeDepot for ~$100.