Question: Intensity for spectra too low?

Can you link to your spectra so I can see?

Here is my latest try: https://spectralworkbench.org/spectrums/89850

Thanks for sharing the link. Because you're using an uploaded image, the top row of pixels is quite dark, and that's the one used as your cross-section line.

I tried forking your spectrum and selecting a new cross-section: https://spectralworkbench.org/spectrums/89900

That looks much better and makes a good calibration. But note that since your spectrum is curved, the choice of cross-section will shift your calibration left or right depending on what height it is. You'll need to ensure all your data has the same cross-section if you want to compare it or use this calibration for other readings.

Hope that helps!

You'll need to ensure all your data has the same cross-section if you want to compare it or use this calibration for other readings.