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# uv-sensor

Arduino sketch for analog UV sensor.


## Description

![Foo](https://www.tinytronics.nl/shop/image/cache/catalog/products/product-003601/uv-light-sensor-module-200-370nm-80x80w.jpg)
Image courtesy Tinytronics

This small (type-less) UV-sensor is powered by 3.3 .. 5 V so it can be used by almost any microprocessor.

The sensor has an analogue output that is roughly linear with the UV-index (sunlight assumed, see notes)


|  Voltage  |  UV index  |  risk of harm  |  Colour   |
|:---------:|:----------:|:---------------|:---------:|
|   <0.050  |     0      |  low           |  Green    |
|   0.227   |     1      |  low           |  Green    |
|   0.318   |     2      |  low           |  Green    |
|   0.408   |     3      |  moderate      |  Yellow   |
|   0.503   |     4      |  moderate      |  Yellow   |
|   0.606   |     5      |  moderate      |  Yellow   |
|   0.696   |     6      |  high          |  Orange   |
|   0.795   |     7      |  high          |  Orange   |
|   0.881   |     8      |  very high     |  Red      |
|   0.976   |     9      |  very high     |  Red      |
|   1.079   |    10      |  very high     |  Red      |
|   1.170>  |    11      |  extreme       |  Purple   |


From this table the formula is derived (spreadsheet) which is pretty linear between UV 1 and 11.

There is an extended library version which has more functionality and documentation.
- https://github.com/RobTillaart/AnalogUVSensor


### Notes

Note: The sensor is not calibrated and the table is indicative for sunlight (assumption!)
and therefore not suitable for e.g. medical or industrial usage.

Note: UV radiation will not go through glass, so inside you will most likely always read zero.
This may help to calibrate the zero level of the sensor.

Note: depending on the light source used, the table above is incorrect.


#### Sensitivity

The sensor is sensitive for wavelengths from 200 - 370 nm, so mostly in UVB and UVA region and less in the UVC.

https://en.wikipedia.org/wiki/Ultraviolet


## Future

Future development will be done in the library version only.
- https://github.com/RobTillaart/AnalogUVSensor