Abstract
Calculations have been made for the partial pressure of OH molecules in argon plasmas into which a small amount of water vapor was introduced through a desolvation device. The Newton-Raphson method was applied to the calculation for a system consisting of O, H, OH, O2, H2, H2O, and argon. In the temperature range above 4000 K, where the system consisted mainly of O, H, OH, and argon, an approximate analytical calculation provided results in a good agreement with those obtained by the Newton-Raphson method. The partial pressures in the plasma jet light source and the high frequency plasma torch were determined by the methods proposed. Calculated ratios of the OH band emission intensities at two different temperatures are also given and are discussed.
