A high-frequency-based measuring device for determining a dielectric constant of a medium comprises a signal-generating unit for coupling an electrical high-frequency signal into a transmitting electrode located in the medium, the transmitting electrode having a depth of at most one quarter of the wavelength of the high-frequency signal; a receiving electrode likewise located in the medium and located a distance from the transmitting electrode of at most one quarter of the wavelength of the high-frequency signal, for receiving the high-frequency signal after the same has passed through the medium; and an evaluation unit designed to determine the dielectric constant on the basis of the received high-frequency signal.

A transparency, e.g. an aircraft laminated windshield, includes one or more moisture sensors to monitor moisture penetration to monitor performance of the moisture barrier. At least one of the moisture sensors includes a dielectric between and in electrical contact with two electrically conductive electrodes. Alternating electrical current is applied to the electrodes to measure the complex impedance (ohms) of the dielectric to determine the amount of moisture within the laminated windshield in the area of the moisture sensor. With the information provided by the moisture sensors performance of the windshield is available to schedule timely repair or replacement of the windshield that is performing outside of acceptable limits.