Abstract: A rain sensor for a motor vehicle is proposed, having a transmitter (16) emitting radiation, a receiver (18), and a holographically embodied diffractive element (22a, 22b) that has a linear-grating-like structure.

Abstract: A process is for the production of potash fertilizer granulates which have a stable shelf life also at high relative air humidities. This granulate contains an additive in the form of magnesium oxide and/or calcium oxide in a fine powder form, which is added by metering in prior to the compacting step. The result is a high final bursting strength even if the granulate is stored in a wet climate.

Abstract: A control apparatus for a heating and/or air conditioning installation, especially in a motor vehicle, which includes at least two modules, each of which is in the form of parallelepiped. Each module is arranged to contain at least one control member and has fastening means for fastening the modules together. A front plate is fitted on the from of the modules, and has at least one aperture through which at least one control member can pass, and/or which is adapted to carry a control knob. The fastening means consist of groves and matching ribs which extend centrally over the whole length of lateral faces of the modules. This enables a rib or groove of one module to be fit into a groove or rib, respectively, of another module.