I’m Guy , product manager of SCiO SDK.
Here are the answers:
- X is the wavelength represented in nm (nanometers).
- Y is dependent on the state of the toggle buttons in SCiO Lab.
- No buttons selected: Raw reflectance spectrum
- Processed (only): Assumes Beer-Lambert model is valid, and transforms the measured signal to be linear with concentration by doing a log transform and adjusting the result for noise and deviations from the model. You can learn more about Beer-Lambert here: http://www.chemguide.co.uk/analysis/uvvisible/beerlambert.html
- Normalized (only): Performs normalization of the signal. This is meant to compensate for changing measurement conditions (e.g. varied scanning distances) that typically occur from sample to sample. Y axis still means reflectance but in normalized units instead of raw reflectance.
- Both Processed and Normalized: First assumes Beer-Lambert model (like processed) and then normalizes the results to compensate for differences in the optical path between samples. This is useful, for example, when there is variation in the thickness of the samples.
Typically, different models and types of samples will require different pre-processing methods. You should both choose the pre-processing method to match your experimental setup and optimize the performance of your model. If you planned and gathered your data correctly, these efforts will coincide.