Abstract: An analyte concentration, in a sample fluid, is determined by differential measurement. Two or more capacitive field effect sensors have an identical basic structure and are arranged in a shared measuring cell. One of the sensors forms a measuring sensor with an active transductor layer. Another sensor forms a reference sensor without an active transductor layer. The sensors are contacted with the sample fluid and the sensors, have an associated reference electrode, or have a shared reference electrode. A bias voltage composed of an electric DC voltage and a superimposed AC voltage is applied between each sensor and associated reference electrode(s) Capacitance changes due to the analyte are eliminated by controlling the bias voltage applied to the measuring sensor in a closed control loop. A measuring signal is obtained by calculating a difference between voltage values representative of DC voltage potentials applied to the measuring sensor and reference sensor, respectively.

Abstract: An analyte concentration, in a sample fluid, is determined by differential measurement. Two or more capacitive field effect sensors have an identical basic structure and are arranged in a shared measuring cell. One of the sensors forms a measuring sensor with an active transductor layer. Another sensor forms a reference sensor without an active transductor layer. The sensors are contacted with the sample fluid and the sensors, have an associated reference electrode, or have a shared reference electrode. A bias voltage composed of an electric DC voltage and a superimposed AC voltage is applied between each sensor and associated reference electrode(s) Capacitance changes due to the analyte are eliminated by controlling the bias voltage applied to the measuring sensor in a closed control loop. A measuring signal is obtained by calculating a difference between voltage values representative of DC voltage potentials applied to the measuring sensor and reference sensor, respectively.

Abstract: The invention relates to a large-surface billboard for outdoors advertising. In order to generate a luminosity of the LCD elements of the billboard, extraneous light is required. In times of insufficient sun light, an artificial lighting device activates the luminosity. The aim of the invention is to prevent the lighting device from casting a shadow onto the billboard during daylight. For this purpose, the lighting device is moved out from its beam path incident on the billboard when there is sufficient solar radiation.

Abstract: A device for suspending posters comprises a poster web that can be driven back and forth between two rolls with longitudinal tensioning in the direction of transport. The rolls are arranged one on top of the other. Each of the lateral longitudinal edges of the web extend in the transport direction. To avoid annoying fluttering of the poster web in wind and weather, a holding device is associated as a lateral guide for the web between the rolls.

Abstract: A device for suspending posters comprises a poster web that can be driven back and forth between two rolls with longitudinal tensioning in the direction of transport. The rolls are arranged one on top of the other. Each of the lateral longitudinal edges of the web extend in the transport direction. To avoid annoying fluttering of the poster web in wind and weather, a holding means is associated as a lateral guide for the web between the rolls.