Here is a view of the hardware ready to do testing. An important recommendation is that the tests should be done in a light controlled environment similar the one I did. These tests cannot be done outdoors due to the strong solar radiation.
This is a screenshot of a healthy leaf.
This other image is a screenshot of an unhealthy leaf.
Below I show you the video where I did tests with three different types of plant leaves.
In the download section you can get the CSV file during the test.