Abstract: A sensor of the present disclosure includes a sensor housing with a housing window; a sensor unit arranged in the sensor housing suitable for emitting a sensor signal through the housing window and for receiving a detection signal through the housing window (3); a cleaning unit having a cleaning element, a holder and a drive, wherein the cleaning element is attached to the holder such that the cleaning element is suitable for contacting the housing window from the outside, wherein the drive is non-positively connected to the holder and is suitable for moving the cleaning element across the housing window; and a pressing unit which is suitable for exerting an adjustable contact pressure on the cleaning unit so that the cleaning element is pressed against the housing window with the contact pressure.

Abstract: A method for turbidity measurement in a measured medium uses a turbidity sensor, which comprises at least a first and a second emitter and at least a first and a second detector. The first and the second emitters are excited one after the other to produce light signals directed into the measured medium; wherein each light signal travels along a first propagation path through the measured medium to the first detector, and is converted by such into a first detector signal; and travels along a second propagation path through the measured medium to the second detector, and is converted by such into a second detector signal. A turbidity value is ascertained based on the first and the second detector signals; wherein, by means of at least one additional detector, to which at least one of the light signals travels along an additional propagation path, an additional detector signal is ascertained, and, on the basis of the additional detector signal, the turbidity value is checked as regards its plausibility.

Abstract: A turbidity measuring device having a four-beam, alternating light arrangement for registering turbidity of a measured medium includes first and second light sources L1, L2; and first and second receivers R1, R2. The direct measuring paths extend from light sources Li, through a measured medium, to receivers Ri, and indirect measuring paths extend from light sources Li, through the measured medium, to second receivers Rj; wherein i?j; wherein turbidity can be ascertained as a function of a quotient A/B by means of an evaluating circuit; wherein A and B are functions at least of signals registered via the direct or indirect measuring paths; wherein at least a first monitor signal, which depends on the first light source, enters into one of the two terms A or B; wherein the light reaches the monitor from the first light source without interaction with the measured medium; and wherein the monitor signal is added to at least one of the signals registered via the measuring paths and entering into the term A or B.

Abstract: A turbidity measuring device for determining the concentration Kj of a substance Sj in a medium includes measuring arrangements, in which the intensities of scattered light at different angles are registered and convertable into current values of at least a first measured variable M1 and a second measured variable M2, which have different dependences on the concentration Kj of a substance Sj (Mi(Kj)=fij(Kj)). The turbidity measuring device has stored for the measured variables Mi for a number of substances Sj calibration functions gij, with which, in each case, a concentration of a substance Sj is determinable (Kj=gij(Mi)). The turbidity measuring device further includes a computing unit, which is suitable for evaluating the ascertained concentration values gaj(Ma), gbj(Mb), wherein a?b, for different substances Sj as regards their plausibility and so to identify a plausible substance Sj, or to check the plausibility of an earlier identified or predetermined substance Sj.

Abstract: A method for turbidity measurement in a measured medium uses a turbidity sensor, which comprises at least a first and a second emitter and at least a first and a second detector. The first and the second emitters are excited one after the other to produce light signals directed into the measured medium; wherein each light signal travels along a first propagation path through the measured medium to the first detector, and is converted by such into a first detector signal; and travels along a second propagation path through the measured medium to the second detector, and is converted by such into a second detector signal. A turbidity value is ascertained based on the first and the second detector signals; wherein, by means of at least one additional detector, to which at least one of the light signals travels along an additional propagation path, an additional detector signal is ascertained, and, on the basis of the additional detector signal, the turbidity value is checked as regards its plausibility.

Abstract: A turbidity measuring device having a four-beam, alternating light arrangement for registering turbidity of a measured medium includes first and second light sources L1, L2; and first and second receivers R1, R2. The direct measuring paths extend from light sources Li, through a measured medium, to receivers Ri, and indirect measuring paths extend from light sources Li, through the measured medium, to second receivers Rj; wherein i?j; wherein turbidity can be ascertained as a function of a quotient A/B by means of an evaluating circuit; wherein A and B are functions at least of signals registered via the direct or indirect measuring paths; wherein at least a first monitor signal, which depends on the first light source, enters into one of the two terms A or B; wherein the light reaches the monitor from the first light source without interaction with the measured medium; and wherein the monitor signal is added to at least one of the signals registered via the measuring paths and entering into the term A or B.

Abstract: A drive slip regulating system is described, in which the speeds of the drive wheels are compared with one another and as a function of the deviation .DELTA. v a set-point brake pressure is calculated, with which the excessively spinning wheel is to be braked. In the pulsed furnishing of the brake pressure, the valve opening times are calculated, taking the pressure buildup function into account, in such a way that the actual brake pressure corresponds to the set-point brake pressure.

Abstract: A sealing for a rotary impeller blade partially extending outwardly from a rotor of an impeller pump includes two sealing strips of plastics, the ends of which abut against the opposing side faces of the blade in the region of a slot found in the rotor, and two respective supporting members of metal. Each supporting member secured to the assigned sealing strips reliably supports the sealing strip whereby the sealing strips resist to vibrations occurring at high speeds of the pump during operation.

Abstract: A versatile system for preventing spinning of driving wheels, especially for commercial road vehicles, is provided by a braking control system in which a logic system responds not only to positive slip (overdriving) of each driven wheel, but also to negative slip (overbraking) thereof and, likewise, not only to over-acceleration, but also to excessive deceleration of the driven wheels. The cycle of control is started by an over-acceleration signal and terminates by the timing-out of a control phase in which hydraulic brake pressure is reduced. Within a control cycle, brake pressure builds up for a driven wheel in response to the simultaneous occurrence of any one of the following four pairs of conditions at that wheel: (a) presence of over-acceleration and of negative slip; (b) presence of over-acceleration and of positive slip; (c) presence of over-acceleration and absence of negative slip, and (d) presence of over-deceleration and of positive slip.

Abstract: A cryopump having a generally axially symmetrical housing provided at one end with an entrance opening defined by a plane for passage of molecules of the gas to be pumped and plates defining condensation surfaces arranged to be brought to low temperature for condensation of molecules of the gas to be pumped, and a thermal radiation shield disposed in the region of the entrance opening, with the condensation surfaces being oriented substantially at right angles to the plane of the entrance opening and the radiation shield being composed of a plurality of elongate metal strips so positioned that their longitudinal axes are parallel to the condensation surfaces.

Abstract: A turbomolecular vacuum pump has a housing, a vertically oriented hollow pump rotor situated in the housing, and a vertically upwardly oriented stub shaft affixed to the housing and extending into the hollow pump rotor. The pump rotor is supported on the stub shaft by a magnetic axial bearing and at least one magnetic radial bearing, all disposed in the space surrounded by the hollow pump rotor.