Abstract: A sensor device for detecting the degree of wetting and/or contamination of windows, especially windshields of motor vehicles, which device has a radiation source (12) emitting a radiation into the window (10) from the inside of the window (10), and a radiation measuring device detecting the radiation reflected many times by total reflection in the window (10) between outer surface (17) and inner surface (18). A heating device (33) is arranged on at least one contact surface between the sensor device and the window (10) or in the window. As a result, the measurement path (19) of the window (10) is deliberately heated with a low energy requirement, so that no measurement impairment is to be feared as a result of condensation on the inner surface (18) of the window and a mirrored reflection surface on this inside is not necessary.

Abstract: A thermal radiation sensor is suggested which comprises two receiver surfaces exposed to the radiation, one receiver surface (1) having a high absorption capacity with respect to the thermal radiation, the other (2) having a low absorption capacity, the two receiver surfaces (1) and (2) consist of a NTC resistance material and are combined in a bridge circuit together with two temperature-independent cermet resistors (3) and (4). In order to prevent a dependency of the measurements of such a sensor on the ambient temperature, the NTC resistors (1) and (2) comprise underlying heating layers (6) and (7) which keep the two NTC resistors at a constant temperature. Insulating layers (8) and (9) are provided between the NTC resistors (1) and (2) and the heating layers (6) and (7). The heating layers (6) and (7) consist of a cermet thick film with platinum or of a platinum thick film and have the shape of a meander. The insulating layers (8) and ( 9) preferably consist of a crystallizing glass.

Abstract: A method of controlling climate in an interior of a vehicle, which method comprises the steps of measuring air temperature in the vehicle interior and outside of the vehicle, measuring relative humidity in the vehicle interior and outside of the vehicle, and controlling air flow from outside of the vehicle into the vehicle interior in accordance with the measured temperatures and humidities.

Abstract: A heat and/or air conditioning apparatus for a motor vehicle comprising control means and a first humidity sensor located in the interior of the motor vehicle, a second temperature sensor and a second humidity sensor located outside of the vehicle, intake duct means for supplying outside air to the vehicle interior, at least two discharge ducts located in the vehicle interior and of which at least one opens in the vicinity of a vehicle window, and a blower.

Abstract: An ion conductive sensor is connected to a current source which, in order to prevent polarization effects, controls current flow through the sensor in spaced or polarity-alternating pulses. If the sensor is a humidity sensor, it is preferably constituted by Cr.sub.2 O.sub.3, V.sub.2 O.sub.5 and Na.sub.2 WO.sub.4 in a proportion, by weight, of preferably 2 to 2.5:1:1, sintered on a substrate which has comb electrodes applied thereto. The sensor is especially immune to noise or disturbance pulses from the current supply and is especially suitable for use as an ambient humidity sensor in an automotive vehicle (810).

Abstract: A heat radiation sensing device is provided, which comprises two receiver surfaces which are exposed to the radiation, one of which comprises a high absorption ability with respect to the heat radiation by means of a black coloring, while the other has a low absorption ability by means of a covering which reflects the heat radiation. These two receiver surfaces consist of NTC resistor material and are combined to form a bridge circuit with two cermet resistors which are independent of temperature. The four resistors are applied to a ceramic substrate and are connected with conductor path which, in turn, end in the four required connections. The ceramic substrate is fixed in a frame which carries a covering which is pervious to heat radiation to a great degree and which, in turn, carries a layer having a window over one of the two NTC resistors the layer is made of a material which reflects the heat radiation to a great degree.

Abstract: A humidity sensor, and particularly a sensor which can distinguish between low humidity values, for example below 60% humidity, and high humidity values, for example 90% humidity and thereover, and change the capacitance between output electrodes (5, 6) is formed by applying interdigited comb electrodes (1, 2) on a substrate (8) and applying over the substrate a ceramic mass formed of BaRuO.sub.3, V.sub.2 O.sub.5 and Na.sub.2 WO.sub.4, with a weight relationship of (1.+-.0.4):(1.+-.0.4):(0.6.+-.0.2) preferably 1:1:0.6. The sensor is made by first making a powder of the components, mixing it with a glass paste and, if necessary, a thinner, and applying the resulting paste by thick-film technology to a ceramic substrate on which the electrodes have been applied, and then firing the substrate at a temperature of between 550.degree. C. to 850.degree. C.