Given the potential of low-cost sensors for agriculture, we evaluated a spectrometer developed with low cost components regarding its static characteristics in leaves of crisp lettuce and kale. Raw and processed measurements were compared to the ones obtained by a reference spectrometer. The analyses in raw and processed readings showed that measurements with low-cost sensors lead to very high errors. Correlation analysis, however, showed that these sensors may be useful when the phenomena of interest is variation in the reading, instead of the reading itself.