2.6 KiB
uv-sensor
Arduino sketch for analog UV sensor.
Description
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 |
|---|---|
| <0.050 | 0 |
| 0.227 | 1 |
| 0.318 | 2 |
| 0.408 | 3 |
| 0.503 | 4 |
| 0.606 | 5 |
| 0.696 | 6 |
| 0.795 | 7 |
| 0.881 | 8 |
| 0.976 | 9 |
| 1.079 | 10 |
| 1.170> | 11 |
From this table the formula is derived (spreadsheet) which is pretty linear between UV 1 and 11.
Related to: 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
- verify vs calibrated sensor.
- investigate angle sensitivity (if the UV light comes from an angle).
- investigate response time to stabilize (e.g. does it react fast on clouds).
- investigate with different light sources (UVled, TL, sunlight).
- allow use of internal / external ADC.
- add a pin to control the power of the sensor (low energy applications).