Abstract: A device for checking the concentration of clear rinsing agent in a rinsing liquid circulated in the means for retaining water of a household appliance is provided. The device includes a processing unit operatively connectable to a sensor having at least one transmitting element that emits an optical signal and at least one receiving element that receives the optical signal emitted by the transmitting element. The processing unit determines the wetting of the sensor with clear rinsing liquid and renders an estimate of the concentration of clear rinsing agent in the clear rinsing liquid as a function of the wetting of the sensor with clear rinsing liquid based upon the energy level emitted by the transmitting element and received by the receiving element.

Abstract: A device is provided for filtering particles from a dishwashing fluid in a dishwashing machine, the dishwashing machine having a dishwashing container in which are disposed items to be subjected to the application of a dishwashing liquid thereto such that particles disentrained from the items during the application of a dishwashing liquid are entrained with the dishwashing liquid. The device includes a container operable to retain therein a predetermined quantity of a liquid mixed with at least one of a foam-forming substance and cleaning agents, the container including an arrangement for producing a flow of a gaseous fluid through the predetermined quantity of the liquid so as to generate a foam layer. The foam layer filters out from a dishwashing liquid passed through the foam layer a substantial fraction of particles entrained with the dishwashing liquid and such filtered-out particles are retained in the foam layer.