Abstract: A device has at least one sensor for determining one or more constituents of a medium flowing in an installation duct. The device has a housing and a main channel, which is connected to said housing and is closed at an end remote from the housing. The main channel has a first channel and a second channel, which is separated from the first channel by a first separating wall. The main channel also has at least one first opening, which is away from the end and creates a first connection between the first channel and the installation duct, and at least one second opening, which is away from the end and creates a second connection between the second channel and the installation duct, so that the medium flows between the openings, through the channels and past the sensor.

Abstract: In a method of determining air humidity, a corrected moisture signal is calculated for a moisture signal (Hi) ascertained from electrical properties of a capacitive moisture measuring element. In a measuring phase (30) with rising relative air humidity (RH), the corrected moisture signal is the current moisture signal (Hi) increased by a correction value, whereas in a measuring phase (31) with falling relative air humidity (RH) the corrected moisture signal is the current moisture signal (Hi) reduced by a correction value. Depending on the respective properties of the moisture measuring element and the required degree of measuring accuracy, the correction value is constant or is taken into consideration in dependence on the relative air humidity RH. This method provides a higher level of measuring accuracy with a moisture sensor equipped with the moisture measuring element.

Abstract: In a method of determining air humidity, a capacitive moisture measuring element (2) used in a moisture sensor for calculation operations is modelled by a parallel circuit of an ideal capacitor (C) and an ohmic resistance (Rp). Charging and/or discharging of the capacitive moisture measuring element (2) by way of a first measuring resistor (R1; RA) provides for ascertaining a first time constant or a first period duration of the charging and/or discharging operation, and charging and/or discharging of the moisture measuring element (2) by way of a second measuring resistor (R2; RA//R) provides for ascertaining a second one. The capacitance (C) of the moisture measuring element (2) is then calculated from the two time constants or the two period durations, a value for the moisture level finally being ascertained from the capacitance. This method achieves a higher level of measuring accuracy on the part of the moisture sensor.

Abstract: An apparatus for detecting the temperature of a room (2) includes means (4) for generating and receiving sound waves, means (5) for determining the transit time of the sound waves for a certain distance (x) in the room (2) and means (10) for calculating the temperature (U) of the room (2) by means of the ascertained transit time (t) of the sound waves for the distance (x) in the room (2). An approximation procedure for ascertaining the distance (x) is automatically executed. The temperature (U) ascertained in that way corresponds to a mean room temperature over the distance (x).