The measurement of water in hydrocarbon solvents is an important measurement in many industrial 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, propane, tetrahydrofuran, methyl-isobutyl ketone in addition to fuels such as petroleum and aviation gasoline. 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 - 2500nm. 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 DCP007NIR photometer is well suited for the detection of water in hydrocarbons. The Kemtrak DCP007NIR photometer measures at two wavelengths. A primary wavelength is used to measure the water while a reference wavelength not influenced by water is used to compensate for the hydrocarbon background, turbidity, air bubbles and/or fouling.

Kemtrak offers a comprehensive range of flow-cell manifolds that can be certified for explosive environments (ATEX).

Water in hydrocarbons

Water in fuel