We describe an experimental set-up for the study of the dynamic oxidation of refractory compounds. It includes a plasma torch, a high temperature reactor, and aims to blow a high temperature oxidizing gas through a tubular sample. It has been tested on graphite. The mass loss rate of graphite samples was measured for experimental conditions varying from 1 to 10% for oxygen volume concentration; from 1500 to 2200 K for sample temperature : from 1600 to 3500 K and 60 to 120 m s(-1) for gas temperature and average stream velocity. These results can be roughly accounted for by a solution of the Graetz-Nusselt problem. Local Sherwood numbers are given from measurement of the inner diameter of the sample after oxidation.