A dishwasher determines when the dishes are clean through a combination of sensors and timers. Here's a general overview of how a dishwasher typically determines the cleanliness of the dishes:
Water turbidity sensors: Many modern dishwashers are equipped with water turbidity sensors. These sensors measure the cloudiness or turbidity of the water in the dishwasher during the wash cycle. Initially, the water is clean, but as food particles and other contaminants are removed from the dishes, the water becomes cloudier. The turbidity sensors detect when the water reaches a certain level of cleanliness, indicating that the dishes are likely clean as well.
Temperature sensors: Dishwashers also use temperature sensors to monitor the water temperature during the wash cycle. The water is typically heated to a specific temperature to aid in removing grease, grime, and bacteria from the dishes. If the water reaches the desired temperature and remains at that level for the specified duration, it suggests that the cleaning process is complete.
Timers: Dishwashers have built-in timers that control the duration of each cycle. These timers ensure that the dishwasher runs for the appropriate length of time to complete the cleaning process effectively. Once the predetermined time for a cycle elapses, the dishwasher assumes that the dishes should be clean.
Optics and other sensors: Some advanced dishwashers may use additional sensors, such as optical sensors or infrared sensors, to detect the cleanliness of the dishes. These sensors can analyze the amount of light reflected off the dishes to assess their cleanliness.
It's important to note that while dishwashers employ these sensors and mechanisms to determine when the dishes are clean, they do not guarantee perfect results in every case. Factors such as heavily soiled dishes, improperly loaded dishes, or malfunctioning sensors can affect the dishwasher's ability to accurately determine cleanliness.