NIR Biomass Analysis Gone Wrong
![Description English: Ethanol near IR spectrum. I took this spectrum using an Ocean Optics near IR (NIR-512) temperature-regulated InGaAs detector spectrometer [1] with IR fiber optic light guide. This is a very rough spectrum and should not be used for any kind of quantitative data whatsoever. I took it by shining the light from a halogen lightbulb through a tiny (~20ml) beaker of liquid ethanol (~2cm liquid optical path) and into the fiber optic of the spectrometer (I subtracted the spectrum of the empty beaker before taking this one). The spectrometer was not really intended to be used this way and it is a very sloppy way to take a spectrum! Nonetheless, based on comparing it to simillarly taken spectra of water and methanol (and other professionally traken nir ethanol spectra), with the exception of the region between about 1400 and 1600nm (this region is saturated by very strong absorbance), I think it likely fairly accurately shows real features of the NIR spectrum of this compound. Date 10 September 2006 (original upload date) Source Transferred from en.wikipedia to Commons by Sevela.p using CommonsHelper. Author The original uploader was Deglr6328 at English Wikipedia.](https://kemal.yaylali.uk/cdn-cgi/image/format=auto,slow-connection-quality=30,onerror=redirect/https://kemal.yaylali.uk/wp-content/uploads/2025/11/Ethanol_near_IR_spectrum.png)
I recently had to audit a production NIR spectroscopy system used for biomass analysis. On paper, it sounded impressive: “state of the art chemometrics,” “advanced multivariate calibration,” “industry ready models.” In reality? It was a textbook example of how to do NIR modeling wrong in ways that quietly transfer risk and liability from the software vendor… Read More: NIR Biomass Analysis Gone Wrong »