The profiles of temperature and major species concentrations of a CVD reactor were measured and the overall rate constant for the gas-phase reaction was calculated based on the measured data using the Benson and Shaw reaction mechanism, Despite the fact that the mechanism is based on relatively short residence time (order of 1 s) and our CVD is based on longer residence time (order of 100 s), our study showed that the mechanism could be used in the temperature range lower than 1073 K. This finding supports the use of the Benson and Shaw mechanism in our previous computer simulations. (c) 2006 Elsevier B.V. All rights reserved.