Abstract: A laboratory measurements program has been performed in the JF-10 high enthalpy shock tunnel,which provides the aerodynamic and aerothermal conditions wherein plasma envi-ronment issues can be quantitatively examined.Electron number density is measured by a swept-voltage electrostatic probe placed on a 10 degree wedge model.Dual-cable method is explored in order to reduce the induced noise due to the RC characteristic of coaxial cables when a high fre-quency swept voltage is applied to the probe.Results show that electron density in the boundary layer of the model can be effectively acquired and the dual-cable method turns out to be an effec-tive way for electron density measurement in the short duration test facilities.