Why NIR Calibration Models Need Ongoing Checks
Near-infrared spectroscopy relies on calibration models that connect spectral patterns to known sample properties. If the materials being tested change outside the original calibration range, the model may become less reliable.
Model drift can be caused by new raw material sources, seasonal variation, particle size changes, moisture differences, temperature shifts, instrument ageing, lamp changes, or changes in sample presentation. Even small changes can affect spectra if they were not represented in the original calibration set.
Drift does not always mean the instrument has failed. It often means the model needs validation, adjustment, or expansion with new representative samples. Routine checks against reference methods help confirm whether the model is still suitable for the application.
Maintaining Reliable NIR Performance
For more detail on the method, review PAS’s overview of Near Infrared Spectroscopy technology. To compare suitable instruments, explore PAS’s NIR analysers through Portable Analytical Solutions, or contact our team to discuss model validation, calibration updates, and routine measurement requirements.