Method to minimize the temperature drift of optical turbidity sensors

A sensor for performing optical transmission measurements in a domestic electrical appliance, the sensor comprising:

• a sensor housing;
• a light source accommodated in the sensor housing;
• a first light detector and a second light detector, both accommodated in the sensor housing, wherein the first light detector is arranged at an end of a first light-measuring path which begins at the light source and passes over a portion of its path length through a measuring space outside the sensor housing, wherein the second light detector is arranged at an end of a second light-measuring path which begins at the light source and runs wholly outside the measuring space outside the sensor housing;
• and
• a solid-material light-conducting structure, wherein both the first light-measuring path and the second light-measuring path extend at least partially inside the light-conducting structure.

A sensor for performing optical transmission measurements in a domestic electrical appliance, the sensor comprising:

• a sensor housing;
• a light source accommodated in the sensor housing;
• and
• a first light detector and a second light detector, both accommodated in the sensor housing, wherein the first light detector is arranged at an end of a first light-measuring path which begins at the light source and passes over a portion of its path length through a measuring space outside the sensor housing, wherein the second light detector is arranged at an end of a second light-measuring path which begins at the light source and runs wholly outside the measuring space outside the sensor housing, wherein the second light-measuring path satisfies at least one of the following conditions:
• the second light-measuring path runs over its entire path length inside and at a distance from an outer surface of the sensor housing;
• no light running along the second light-measuring path leaves the sensor housing;
• no light running along the second light-measuring path passes through a space outside the sensor housing which is fluidically connected to the measuring space outside the sensor housing;
• and
• an intensity of light received by the second light detector via the second light-measuring path is unaffected by a medium through which the first light-measuring path passes in the measuring space outside the sensor housing.