Transfer of grain calibrations between a handheld and a process instrument

Author Summary: Transfer of calibrations between instruments is a key issue to use the value of a calibration over multiple units. Transfer is relatively easy between spectrometers of the same type but can be problematic between different instrument models. Two hundred and seventy samples of wheat from Northern Italy were scanned using a Corona Extreme and an Aurora handheld NIR. Samples (n = 46) from three different locations were removed from the original dataset and used for external validation. The PLS calibrations performances were satisfactory, with SECV for Moisture of 0.09 % and 0.13 % and for Protein of 0.28 % and 0.45 %, respectively for Aurora handheld NIR and Corona Extreme. Performance of validation (SEP) within instrument was of 0.07 % and 0.11 % for Moisture and of 0.27 % and 0.37 % for Protein, for the handheld and the process instrument, respectively. When the same calibrations were used to predict samples across instruments, the SEP was of 0.08 % and 0.19 % for Moisture and of 0.34 % and 0.47 % for Protein, for Corona Extreme predicting Aurora handheld NIR and vice versa, respectively. Both instruments can accurately predict the parameters of interest on wheat and could use the same calibration avoiding time-consuming standardization procedures.