We got some cool "recognizable" spectra for some plastics. But almost no signal for sample that are too or too translucid (especially thin-film)
While using all the tricks of averaging, denoising and deconvolution we are very close to the limit of detection .
We still need to increase SNR to detect broader spectral bands on opaque plastics and/or see some signal on dark plastics.
What would be the cheaper way? a faster ADC (reducing noise by averaging) or switch to a reflection grating (increasing optical signal)?... We may end up trying both ^^
We also need to modify the geometry of the sample holder to be able to detect thin plastic film (like PET) by retro-diffusion.