Detecting UV marks using a UV sensor

How can i detect from a distance of 1-2cm, in a low light environment, a line drawn on paper by a UV marker such as the following UV markers:

  1. https://www.directglow.com/Invisible_In ... _s/108.htm

https://www.ebay.com/itm/353313822362?s ... 2749.l2649

What UV sensor should i use? Do UV sensors have an internal UV LED or would i need to add a LED that lights the paper? If i need to add a LED, what kind of LED should i use?

roineust

I am confused! Are you wanting to detect UV light or visible light when something is excited by UV light?

Paul

Any visible light camera will work to detect the lines, when they are illuminated by UV light.

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How can i detect from a distance of 1-2cm, in a low light environment, a line drawn on paper by a UV marker

If the background "white" is rather uniform, you "may" be able to get by with something like this:
https://www.adafruit.com/product/1334

UV LEDs are not all uniform, different wavelengths will cause the dyes to produce different intensities as well different UV intensities. Getting a project calibrated may be more hit-n-miss.

Investing in a Raspberry Pi and camera running AI may be more reliable as the system is trainable:
https://www.electronicdesign.com/technologies/iot/article/21144340/building-an-ai-camera-with-a-raspberry-pi

I want to find the simplest analog output sensor, that can detect the UV mark, when iluminated by UV light.

Please be more forthcoming with the environment you are suggesting. Dark room? Normally light room? Outside at night? Outside in sunlight? You just mention low light, but what does that mean? Your low light is not my low light,
Have you tested any sensors for your project?

Paul

Test several and choose the simplest that actually works under a variety of conditions. We can't do that for you.

Your choices for analog are only a photo diode or a photo-multiplier tube. Are you willing to make the required lens system or the parabolic mirror?
Paul

Yes, i found out today by testing, that a photo-transistor is able to detect the difference, between a UV marker line reflection over paper, when a UV LED is pointed at the UV marker line and a blank area on the paper, that the UV LED is pointing at, where there is no UV mark.