Abstract: The invention relates to an apparatus for cleaning a fluid, in particular air, comprising a through-channel for the fluid, a radiation source device and a photocatalysis device, wherein the radiation source device emits electromagnetic radiation, wherein, in order to generate a photocatalytic reaction, the photocatalysis device can be exposed to at least some of the electromagnetic radiation, wherein a sensor device is provided to detect at least one change in radiation parameters of the electromagnetic radiation, wherein a control device is connected to the sensor device via signals, and wherein at least one control parameter of the radiation source device can be modified by means of the control device in the case of a deviation of the radiation parameter from a setpoint/threshold value or setpoint/threshold range.

Abstract: An optical sensor to measure the turbidity of wash water in a household washing machine or dishwasher, includes a housing having a housing interior containing a measurement module having a light-emitting element and a light-receiving element, the measurement module defining a measurement light path which extends from the light-emitting element to the light-receiving element and passes outside the housing over a part of its path length. The light-emitting element and the light-receiving element are arranged together in a first subspace of the housing interior, and the measurement light path extends over a part of its path length through at least one second subspace of the housing interior, which is sealed from the first subspace. All the electrical/electronic components of the measurement module are fitted in the first subspace, so that any ingress of wash water into the second subspace does not compromise the electrical functionality of the sensor.

Abstract: An optical sensor to measure the turbidity of wash water in a household washing machine or dishwasher, includes a housing having a housing interior containing a measurement module having a light-emitting element and a light-receiving element, the measurement module defining a measurement light path which extends from the light-emitting element to the light-receiving element and passes outside the housing over a part of its path length. The light-emitting element and the light-receiving element are arranged together in a first subspace of the housing interior, and the measurement light path extends over a part of its path length through at least one second subspace of the housing interior, which is sealed from the first subspace. All the electrical/electronic components of the measurement module are fitted in the first subspace, so that any ingress of wash water into the second subspace does not compromise the electrical functionality of the sensor.