Never touch or clean grating. Room should be free from vibration and have stable and dedicated electrical current. Sample must be dried and ground by the same methods as those samples used to develop the calibration equation. Spectrophotometer reads only a fraction of 1 mm depth of material touching glass of sample container. Therefore container must be loaded carefully with different subsample in each quadrant to make spectral reading more representative of entire sample.
Prediction is made by direct comparison to calibration.
No additional calculations. If calibrations were made using reference values on a dry matter basis, NIR results will be expressed on a dry matter basis. Include at least one set of duplicates in each run. These duplicates must be two subsamples each packed in a separate holder. Quality control for NIR analysis involves monitoring the accuracy of both the instrument and the calibration equation.