Patent ID: 9714901
Date: 2017-07-25
CPC Classifications: G01N

Claim:
1. A device for measuring a nitrate-nitrogen concentration in soil based on attenuation over a spectral operating range, the device comprising: a light source that generates light that spans the spectral operating range, the spectral operating range including wavelengths at least as short as 230 nm; a detector having a sensitivity that spans the spectral operating range; a sample chamber configured to contain a soil-extractant mixture, the light propagating from the light source to the detector and attenuated by the soil-extractant mixture in the sample chamber, the detector generating a soil spectral signal that indicates the light received by the detector at different wavelengths across the spectral operating range; and a processor coupled to the detector, wherein the processor estimates an attenuation spectrum of the soil-extractant mixture over the spectral operating range based on the soil spectral signal, and estimates the nitrate-nitrogen concentration based on the attenuation spectrum, wherein the processor, when estimating the attenuation spectrum, removes interference in the soil-extractant mixture using one of spectral deconvolution and curve-fitting.