| 摘要 |
The invention relates to a method for operating a washing machine (1), comprising a container (2), a drum (3) for accommodating laundry items (4), a drive motor (5) for the drum (3), an impedance sensor (9) in the container (2) for determining an impedance signal in dependence on a composition of an aqueous liquid (7) in the container (2), and a control device (8), wherein the following steps are performed: (a) providing a sufactant-containing aqueous liquid (7) having a surfactant concentration cTensid in the container (2) in such a way that the relation CCMC ≤ cTensid < Cgrenz is satisfied, wherein CCMC is a critical micelle concentration; (b) measuring the surfactant concentration CTensid in the surfactant-containing aqueous liquid provided in step (a) by capturing and evaluating impedance signals of the impedance sensor (9) by using a relationship between the impedance signals and the surfactant concentration, which relationship is stored in the control device (8); (c) performing a washing phase in such a way that, (c1) in the case a determined surfactant concentration CTensid ≥ Cgrenz, the surfactant-containing aqueous liquid is thinned until the relation CCMC ≤ CTensid < Cgrenz is satisfied; (c2) in the case of a determined surfactant concentration CTensid < CCMC, additional detergent is added in a metered manner and/or a motion program of the drum (3) stored in the control device (8) for this surfactant concentration is performed. The invention further relates to a washing machine (1) suitable for performing the method. |
