Monitoring granulation and drying

Water is also a common source of error in NIR measurements. Variable water content can cause significant changes in sample spectra, and unless such moisture variations are included in a calibration, NIR-predicted 

As an example of the error that may be induced in NIR measurements by failure to control humidity, fluctuations in the concentration of atmospheric water vapor generated by an air conditioner were identified as a source of noise in NIR spectrometers in a 1987 paper [3]. 

In 1968, Sinsheimer and Keuhnelian used the 1900 nm absorption band of water to quantify water with the same accuracy as Karl Fischer titration [5]. This is a combination band of fundamental stretching and 

Pharmaceutical and medical applicaticms of near-infrared spectroscopy 

In 1970, Warren et al. addressed the determination of trace amounts of water in mono-, di-, and triglycerides by NIR spectrometry [7]. Using chloroform as a solvent, the investigators studied the combination band of water occurring at 1896 nm in the presence of the -OH groups on glycerides to determine water down to 0.05%. 

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