Light Absorption by Hydrocarbon Molecules at 3.392 µm of He-Ne Laser

Abstract

The decadic molar extinction coefficients of various hydrocarbon molecules at the wavelength of 3.392 µm of the infrared He-Ne laser were measured at temperatures between 292 and 1100 K using the shock-tube technique. Methane, ethane, propane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, iso-octane, methanol, ethanol, butanol, acetone and benzene absorbed the laser light. No Doppler-or pressure-broadening of these molecules was observed except in the case of methane and ethane. The values of the decadic molar exctinction coefficients give information on a temperature-measurement technique which utilizes Beer-Lambert's law.