Method and device for detecting a water change in a water-bearing household appliance, in particular a dishwasher

Abstract

The present invention relates to a method and device for dispensing a rinse aid preparation into the interior of a dishwasher comprising a sensor for detecting water, a sensor for detecting temperature, a control unit for processing the sensor data, wherein the control unit is configured to perform the method according to the invention.

What is claimed is: 
     
         1 . A method for detecting a water change in a water-conveying domestic appliance, in particular a dishwasher, comprising:
 a sensor for detecting water;   a sensor for detecting temperature;   a control unit for processing the sensor data;   wherein the method comprises the following steps:
 (a.) detecting water in a defined time interval ZI w,1  of 2-120 s, wherein method step (b.) is performed after the absence of water has been detected at at least two, consecutive measuring points within a time interval ZI w,1 , 
 (b.) detecting water in a defined time interval ZI w,2  of 1 ms-120 s, wherein method step (c.) is performed after the presence of water has been established at least once within the time interval ZI w,2 , 
 (c.) detecting the temperature in a time interval ZI T,3  of 2-120 s, preferably 5-60 s, wherein method step (d.) is performed if, at at least two, consecutive temperature measuring intervals ZI T,4  within the time interval ZI T,3 , the temperature T 1  at the start of the measuring interval ZI T,3 is greater than the temperature T   2  at the end of the measuring interval ZI T,3 , 
 (d.) performing method step (e.) if the time between the detection of water according to method step (b.) and at least three consecutive detections of a negative temperature gradient according to method step (c.) is less than two minutes, 
 (e.) generating a control signal by the control unit on the basis of a detected water change according to method steps (a.) to (d.). 
   
     
     
         2 . The method according to  claim 1 , wherein the control signal, after a detected water change, effects dispensing of a rinse aid preparation into the interior of a dishwasher. 
     
     
         3 . The method according to  claim 1 , wherein the method comprising method steps (a.)-(e.) is performed once at least one first dishwashing preparation has been released into the interior of the dishwasher, wherein the at least first dishwashing preparation is released when at least a temperature of >25° and the presence of water have been detected. 
     
     
         4 . The method according to  claim 1 , wherein the method, comprising method steps (a.)-(e.), is performed, after the release of the first dishwashing preparation, once at least one second dishwashing preparation, has been released into the interior of the dishwasher. 
     
     
         5 . A device for dispensing a rinse aid preparation into the interior of a dishwasher comprising:
 a sensor for detecting water;   a sensor for detecting temperature;   a control unit for processing the sensor data;   
       wherein the control unit is configured to perform the method according to  claim 1 . 
     
     
         6 . The device according to  claim 5 , wherein the device is freely positionable by a user in the interior of a dishwasher. 
     
     
         7 . The device according to  claim 5 , wherein the device comprises a cartridge having at least one chamber in which at least one rinse aid preparation is stored. 
     
     
         8 . The device according to  claim 7 , wherein the cartridge comprises at least three chambers, in which an enzyme-containing preparation, an alkaline preparation and a rinse aid preparation are stored. 
     
     
         9 . The device according to  claim 5 , wherein the control unit is couplable, in particular wirelessly, with the existing controller of the domestic appliance.