Device for measuring moisture in substrate and health of hair

摘要

A sensor for measuring moisture content of a substrate, comprising: a coplanar waveguide; a directional coupler having a pair of generally parallel first and second strips defining a coupling gap therebetween; and a high frequency signal generator electrically coupled to said first strip and operable to couple power to said second strip with the substrate placed across said coupling gap to thereby generate a coupled power signal in said second strip having an amplitude related to moisture content of the substrate.