NIR Spectroscopy Laboratory Guide
A practical guide to NIR spectroscopy in the laboratory: FT-NIR vs dispersive vs filter instruments, Beer-Lambert law, sample preparation, and method development.
How NIR Spectroscopy Works
NIR Instrument Types
Sample Preparation: Where Most NIR Errors Start
Frequently Asked Questions
- What is the difference between FT-NIR and dispersive NIR?
- FT-NIR (Fourier Transform) uses an interferometer to collect all wavelengths simultaneously, then applies a mathematical transform to extract the spectrum. Dispersive instruments use a diffraction grating or filter to isolate individual wavelengths s...
- Why does sample temperature matter for NIR?
- Temperature shifts the position of water and lipid absorption peaks slightly — a 10°C change can cause 0.5–2% errors in moisture or fat predictions. Professional NIR analyzers control sample temperature (usually 40°C for liquids, room temperature for...
- What is Beer-Lambert Law and when does it break down?
- Beer-Lambert Law states that absorbance is proportional to path length and concentration: A = abc. This holds true for dilute, homogeneous solutions. In food and agriculture, it often breaks down because samples are turbid (scattering light), heterog...