Vapor diffusion coefficient unstable state measuring device

The utility model discloses a vapor diffusion coefficient unstable state measuring device. The device includes: environmental chamber for provide high hygrometry environment, the organic glass case holds anhydrous calcium chloride in for provide low hygrometry, the compulsory convection ware for it is even to make the inside hygrometry of box, capacitanc hygrometry sensor for inside and the environment hygrometry of survey need checking sample, data collection station for gather the hygrometry of hygrometry sensor survey and the survey time that corresponds, and the computer for the fick second law that combines expression vapor unsteady -state diffusion and the inside hygrometry of sample and the survey time that corresponds, utilize the processing of boltzmann transform indirect problem to obtain vapor diffusion coefficient under the need checking sample difference hygrometry. The utility model has the characteristics of simple structure, measurement accuracy height and test time are short.