Self -cooled dew point hygrometer

The utility model provides a self -cooled dew point hygrometer, the tight cover in high vacuum insulation pipe upper end has the upper cover, is provided with pressure connection and exhaust hole in the upper cover, and wherein, pressure connection is used for being connected with the stabiliser, the tight cover of high vacuum insulation pipe lower extreme has a lower cover, and the lower cover is embedded to have the signal line, the center tube is installed to high vacuum insulation intraduct intermediate position, and top -down is around there being the capillary on the center tube, and the capillary upper end links to each other with pressure connection, and just to there being a sensitization mirror surface, the temperature -sensing element has been inlayed at sensitization mirror surface center to the capillary end, and the bilateral symmetry of sensitization mirror surface distributes and has light emitting component and light receiving element, and temperature -sensing element, light emitting componen