Abstract: In a moisture sensor for monitoring the moisture content of layers, at least two parallel electrical conductors connected to a measuring apparatus are disposed adjacent the layers to be monitored. The conductors are surrounded by an insulating material and carry, at their side remote from the layer whose dielectric coefficient is to be monitored, a metal shielding layer for limiting the measurement field of the sensor.

Abstract: In a method and apparatus for determining the volumetric proportion of water in snow and the density of snow, a probe consisting of at least three parallel, but differently spaced, electrical conductors is installed in an area so that the probe is surrounded by the snow, an electromagnetic signal is applied repeatedly to pairs of the conductors for determining different dielectricity coefficients, wherefrom the actual dielectricity coefficient is calculated based on probe-specific calibration data and the measuring steps are repeated with a different frequency for which the dielectricity coefficients of the water and ice are known and the volumetric parts of the snow, that is of the water, ice and air in the snow cover is calculated using the law of mass conservation.

Abstract: In a moisture sensor for monitoring the moisture content of layers, at least two parallel electrical conductors connected to a measuring apparatus are disposed adjacent the layers to be monitored. The conductors are surrounded by an insulating material and carry, at their side remote from the layer whose dielectric coefficient is to be monitored, a metal shielding layer for limiting the measurement field of the sensor.

Abstract: In a moisture sensor arrangement for large area layers including a high-frequency electrical generator, a signal travel time measuring apparatus and a reflectometer, all connected to a cable system, at least two independent cables of the cable system are arranged so as to have cross-over points with, and being disposed in spaced relationship but sufficiently close t, one another such that a signal transfer can occur at the cross-over points.