2.2.4. Micro spectrometer

Finally, the samples were analyzed using a micro spectrometer Neospectra-micro (Si-Ware, Egypt) mounted on a Raspberry Pi single-board computer. The instrument was controlled using a connection to a PC and the SpectraMOST software was used. Samples were scanned in reflectance mode over 3921 cm⁻¹ to 7407 cm⁻¹ (1350–2550 nm) and a resolution of 66 cm⁻¹. Each sample was measured on three different spots, and each measurement was obtained with a scan time of 28 s. A white reference (SRS99, Spectralon®) signal I0(λ) was collected before each measurement. For each sample, the intensity signal I(λ) was collected and the absorbance signal Aμ(λ) was computed: