GANN HYDROMETTE wood moisture meters with different measuring ranges up to 100 % m.c., including device for wood species-related correction of the readings and automatic compensation for the influence of wood temperature. Moisture meters working according to the resistance measuring method as well as moisture indicators based on the dielectric constant measuring principle for use on set inorganic building materials. Fully and semi-automatic control systems for conventional timber dryers, including central computer for programming and monitoring from the operator's office. Automatic wood moisture measuring, recording and classifying system, designed for use within a continuous manufacturing process.