Optical sensing of low ethanol concentration via absorption rate in visible wavelength

This paper presents the rate of optical absorption in the visible wavelength region for low concentration of ethanol in water. Ethanol absorption rate was measured in neutral, acidic and alkaline medium of potassium permanganate (KMnO₄) dye. The absorption rate was measured for 0.01% to 1% ethanol. This non-contact optical system employs tungsten halogen light source and spectrometer from Ocean Optics. This method demonstrates a sensitivity of more than 0.01%; fast detection speed of 27s; and has potential for in situ measurement.