UV Sensor choice - help needed

Hello! I need an UV sensor and I am not sure which one would be better between those:

and

https://www.adafruit.com/products/1777 (or the smaller version https://www.adafruit.com/products/1981).

I want the sensor to measure as close to the real value as possible but I am not sure which one of them would do so, given the fact that the first one is using a “real” UV sensor, while the second (and third) ones are relaying on IR and VL sensors and some calculus…
Which one would you recommend?

The last but not the least, is the FLORA sensor compatible with an Arduino Uno? I could not find any information on Arduino Board - Flora Sensors compatibility.

Thank you in advance!

Whatever is “better” depends on what you actually want to measure, and how accurately you want to measure it.

Also, the term UV applies a wide range of the light spectrum, so tell us more.

Better as in more precise in the measurement. I want it to be close as possible to the UV index that is used in weather report. Or better said, the UVA and UVB rays that could harm the skin.

The only way to know how well any individual sensor works for a given purpose is to calibrate it.

You can record the sensor output under a range of accurately known standard conditions, or compare its output to that produced by professionally calibrated sensors.

You can do the work yourself or pay to have someone else do it. If neither is an option, you have to decide whether to trust the claims on the data sheet, or product reviews.

Ok, thank you! But can I use the Flora sensor with an Arduino Uno, or I need the other sensor?