TOTAL ENTHALPY PROBES

Enthalpy probes are used for the simultaneous measurement of the locale specific enthalpy, velocity and composition of plasmas. Their main advantage is the simplicity of the technique and its possible use for simultaneous measurement of multiple plasma parameters. The specific enthalpy of the plasma is determined through a measurement of the difference between the heat load on the probe cooling circuit under “sampling” and “tare” conditions.During the “tare” phase, from a measurement of the dynamic pressure on the probe tip, the local plasma velocity can be calculated. During “sample” phase it is possible to analyse flow chemical composition. Knowing the specific enthalpy of the plasma, ho, and its composition, xo, the plasma temperature can be calculated using available thermophysical data.