Answers come from the QuantaDose product page, the Amazon listing, and common questions in Amazon reviews.
What is the QuantaDose 1st Edition card?
A reusable, credit-card-sized UVC test card. In about 15 seconds it runs three tests: a UVC wavelength test (the letters UV-C glow green), a wideband photochromic UV indicator that turns purple, and an intensity check where the word ULTRAVIOLET becomes readable once UVC intensity reaches about 300 µW/cm². Put simply, it checks whether a light gives off optimal germicidal UVC wavelengths, and whether UVC intensity reaches a minimum of about 300 µW/cm².
Source: www.quantadose.comWhy is it called a 3-in-1 card?
Because it runs three tests: a UVC wavelength test (the letters UV-C glow green), a wideband photochromic UV indicator that turns purple, and an intensity check where the word ULTRAVIOLET becomes readable once UVC intensity reaches about 300 µW/cm². The intensity check is calibrated under UVC. The purple strip darkens much more easily under UVA/UVB than under UVC, so for UVC rely on the green UV-C letters and the ULTRAVIOLET word.
How do I use it?
Hold the card under the light for about 15 seconds. If the letters UV-C glow green, the light is putting out germicidal UVC. Remove the card and check the bottom intensity area right away. If you can read the word ULTRAVIOLET, intensity is at least about 300 µW/cm². Safety: UV light can harm your eyes and skin, so wear proper safety equipment to protect them whenever you expose the card to the light. If the device you're testing, such as a UV sanitizer box, doesn't let you see the card while it's under the light, place your phone inside next to the card recording video, then watch the recording to see whether the green UV-C lit up. The fluorescent readout only shows while the card is in direct light.
Source: www.quantadose.comDo I need safety equipment?
Yes. Safety: UV light can harm your eyes and skin, so wear proper safety equipment to protect them whenever you expose the card to the light.
Source: QuantaDose (Quanta X Technology)
How do I test a UV sanitizer box I can't see into?
If the device you're testing, such as a UV sanitizer box, doesn't let you see the card while it's under the light, place your phone inside next to the card recording video, then watch the recording to see whether the green UV-C lit up. The fluorescent readout only shows while the card is in direct light.
Source: QuantaDose (Quanta X Technology)
What does the green UV-C glow mean?
The top window uses an ink formulated to fluoresce green only under optimal germicidal UVC. It will not fluoresce under visible light, UVA or UVB, so a green UV-C means germicidal UVC is reaching the card.
Source: www.quantadose.comWhich wavelengths make it glow?
The 1st Edition product page says only wavelengths between 250–275 nm glow green. The Amazon listing describes temporary fluorescence between 250–270 nm under optimal germicidal UVC.
Source: www.quantadose.comWhat does it mean when I can read ULTRAVIOLET?
The intensity test uses calibrated word legibility. The word ULTRAVIOLET first becomes legible at about 300 µW/cm² during exposure to optimal germicidal UVC wavelengths.
Source: www.quantadose.comWhy did the green glow disappear when I moved the card away?
That's normal. The fluorescence stops within nanoseconds of the light being removed, so read the UV-C window while the card is still under the light.
Source: www.quantadose.comWhen should I read the intensity area?
Immediately after exposure. The photochromic dosimeter color is temporary, and checking it right away gives the most accurate intensity result. The test is complete in 15 seconds, so then remove the card from the source.
Source: www.quantadose.comWhat do the shades on the intensity strip mean?
According to the Amazon listing, the strip is sensitive to wide-band UV between 200–400 nm. A darker color means higher intensity, and at max value shorter wavelengths give a lighter color.
Source: www.amazon.com (Amazon listing)How can I tell if a UV light I bought online is fake?
Put the card under it. Real germicidal UVC makes the UV-C letters glow green. If nothing glows, the light is not producing optimal germicidal UVC. QuantaDose calls the card a consumer's front-line defense against fake UVC products sold online.
Source: www.quantadose.comDoes distance from the light matter?
Yes. The farther the card is from the light source, the less UVC reaches it. When the distance doubles, only about a quarter of the UVC remains.
Source: www.quantadose.comCan I check whether my sunglasses block UV?
The product page lists detecting counterfeit UV-rated sunglasses among the card's off-label uses. One Amazon reviewer wrote: “Handy to keep in pocket/wallet/bag. Easy test for sunglasses.”
Source: www.amazon.com (Amazon listing)Can I test my car or home window tint?
Yes. The product page suggests it as an off-label use. One Amazon reviewer wrote: “As expected, windshield provided good UV protection, but the side windows don't. I measured the UV before and after getting the windows tinted.”
Source: www.amazon.com (Amazon listing)Can I check a reptile or turtle UV lamp?
The product page says the card is useful for reptile owners who want to make sure a harmful light isn't being used on their pets while also testing bulb intensity. One Amazon reviewer wrote: “This is accurate and very helpful to measure UV rays for my Turtle!”
Source: www.amazon.com (Amazon listing)Can I use it to decide when to put on sunscreen?
No. Per the required FDA notice, the photochromic material should never be used to decide when to apply sunscreen or to prevent sunburn. Ask your doctor for sunscreen advice.
Source: www.quantadose.comSome reviewers say sunlight UV-index readings look off. Why?
Sunlight readings are an off-label use. The product page says the card's one intended use is UVC testing: verifying UVC wavelength and showing a minimum UVC intensity.
Source: www.quantadose.comIs it reusable?
Do I still need a UVC meter?
QuantaDose designed the card as a low-cost, in-your-pocket check that saves you spending hundreds of dollars on fragile UV and UVC meters. One Amazon reviewer wrote: “Good product, but pricy. It works; compared using an actual UVC meter and yielded same results....”
Source: www.quantadose.comHow big is it?
How is it different from the 2nd Edition?
For general UVC analysis, the 1st and 2nd Edition cards perform the same. The 2nd Edition adds durability for higher-power commercial use.
Source: www.quantadose.comWhere can I buy it, and what does it cost?
It's sold on quantadose.com and on Amazon. Prices change, so check the product page or Amazon listing for the current price.
Source: www.quantadose.comWho do I contact with questions?
Do the cards expire? What is the shelf life?
We recommend replacing your card about once a year. That said, Quanta X Technology has tested properly sealed, unused cards over three years old and they still work like new. Store cards sealed, away from light and moisture.
Source: QuantaDose (Quanta X Technology)
Will sunlight wear out the card?
Yes. Sunlight and other UV slowly use up the card, so keep it out of the sun. Quanta X Technology says leaving a card in direct sunlight can burn it out in about an hour. Keep each test to about 15 seconds and store the card away from light and moisture between tests, for example in its black UV-resistant sleeve if it came with one, or anywhere dark and dry.
Source: www.amazon.com (Amazon listings, checked Nov 4, 2026)What do customers say? How are the reviews?
On Amazon, as checked November 4, 2026: the 1st Edition averages 4.5 out of 5 stars from 732 ratings, the 2nd Edition 4.5 stars from 561 ratings, and the 3rd Edition 6-in-1 4.4 stars from 307 ratings. Common themes are that it's easy and fast to use, and that it catches fake UVC sanitizers. One reviewer wrote, "I had 3 different UVC lights for sanitizing and only 1 is worth the money." People also use it to check sunglasses, car windows and reptile lamps. Some reviewers say sunlight or UVA/UVB readings can be hard to judge; the card is mainly designed for testing UV light sources.
Source: www.amazon.com (Amazon listings, checked Nov 4, 2026)Who makes QuantaDose? Tell me about the company.
QuantaDose is a brand of Quanta X Technology LLC, an American company in Seminole, Florida, founded in 2020 at the start of the pandemic. The team has engineering and biochemistry expertise, and its mission is to make tools that help fight pathogens. Besides the UVC test cards, Quanta X Technology does Far-UVC lighting design and manufacturing, with Far-UVC advisers to help people pick the right lighting. The company sells online.
Source: www.quantadose.comWhere can I buy QuantaDose cards?
You can order at quantadose.com or on Amazon. Quanta X Technology is the company that makes the cards, but orders aren't placed on a quantaxtechnology site. For questions, email info@quantadose.cards or call +1 (800) 713-9004.
Source: www.quantadose.comWhat are the indicators on the card made of?
The cards use special indicator inks, called analytes. There are fluorescent inks that glow green under UVC, or reddish-pink under UVA/UVB on the 6-in-1, and a photochromic ink that turns purple to show intensity. The 2nd Edition is printed on UV-resilient PVC made for high-power UVC. The exact ink formulas aren't published; for more detail I can forward you to a Quanta X Technology associate.
Source: www.quantadose.comHow does the glowing part of the card work?
In general science terms, a fluorescent material absorbs invisible UV light and gives it back right away as visible light, which is why you see a color glow. It only glows while the UV is hitting it and stops as soon as the light is removed. On QuantaDose cards, the ink in the UV-C letters is chosen to glow green under germicidal UVC, and on the 6-in-1, a longwave ink glows reddish-pink under UVA/UVB. That's why you read the green or pink while the card is still under the light.
Source: General science (not a product claim) ·
Card details: www.quantadose.comHow does the purple strip work?
In general science terms, a photochromic material changes color when UV light hits it, because the UV changes the shape of its molecules, and then it slowly fades back to clear once the UV is gone. Stronger UV changes more molecules, so the color is darker. On QuantaDose cards, the photochromic strip is clear before exposure and turns shades of purple after about 15 seconds under UV, giving a rough intensity reading. Read it right after you take the card out of the light, before it fades. It darkens more easily under UVA/UVB than UVC.
Source: General science (not a product claim) ·
Card details: www.quantadose.com
