What is NIR?
Infrared light lies between the visible and microwave portions of the electromagnetic spectrum. Infrared light has a range of wavelengths, just like visible light has wavelengths that range from red light to violet. Near infrared (NIR) light is closest in wavelength to visible light.
NIR spectroscopy measures how light and matter interact. When light (or near infrared) shines on or through a material, the amount reflected or absorbed depends on the composition of that material. By carefully measuring the light, therefore, we can learn about the nature and composition of the material.
The modern application of NIR is used to measure the composition of unknown samples. It has become a very popular technique in a wide variety of industries due to its speed, accuracy, wide applicability and avoidance of extraneous chemicals.
The basis of NIR analysis is the presentation of a set of samples to an NIR spectrometer. After the spectrometer measures the samples, sophisticated mathematical calculations relate those measurements to known properties (including the composition) of the samples.