Water detection

The measurement of water in alcohols or hydrocarbon solvents is an important measurement in many pharmaceutical processes. The use of near-infrared (NIR) spectroscopy for water analysis is common as NIR offers high sensitivity and measurements can be undertaken in-line providing immediate results.

Water measurements can be undertaken on hydrocarbon solvents with ppm accuracy. Proven applications include acetone, isopropyl benzene, propanol, tetrahydrofuran, and methyl-isobutyl ketone, to name just a few. Additionally, water can be measured in alcohols, such as methanol and ethanol, from trace amount to virtually 100% water.

Water has two regions of activity in the NIR region between 1000 – 2000nm. At 1400nm the O-H stretch in the water molecule is measured, while at 1900nm water has a unique peak due to a combination of O-H stretch and
H-O-H bending. The water peak at 1900 is about five times as large as the water peak at 1400.

The Kemtrak DCP007-NIR LED photometer uses a long life high performance NIR LED light source with robust fiber optics to provide drift and noise-free measurement with very high precision. Automatic compensation for sample turbidity and/or fouling of the optical windows ensures trouble free operation.

Alcohol measurement information sheet

Kemtrak offers a comprehensive range of hygienic process measurement cells and immersion probes that are well suited for explosive atmospheres.