Which sensor automatically deactivates irrigation to save water?

• A. Temperature Sensor
• B. Rain Sensor
• C. Humidity Sensor
• D. Flow Sensor

Answer: (B)

Rain sensor detects rainfall and automatically tells the irrigation controller to suspend watering, preventing unnecessary irrigation after rain and saving water. It’s wired to the controller so when rain is detected, it blocks the next scheduled cycle or any active cycle until conditions dry and reset. This direct action to stop irrigation makes it the best fit for automatic water savings.

Temperature sensors adjust or inform scheduling for temperature-related factors, but they don’t inherently stop irrigation during rain. Humidity sensors measure moisture in the air or soil but aren’t typically used to shut irrigation off automatically in response to rain. Flow sensors monitor how much water is moving through the system and can flag leaks or anomalies, but they don’t automatically deactivate irrigation due to rainfall.