What is an irrigation Rain Sensor?
A rain sensor is simply a switching mechanism activated by rainfall. The device is connected directly or indirectly to a controller which operates an automatic sprinkler system. There are several rain sensor devices on the market but they all share the same purpose and that is to mitigate water usage by preventing an automatic irrigation system to run while it is raining. Most rain sensors will also keep the system shut off for a duration after the rain has stopped.  In most cases the system will not shut down until enough rain water is absorbed by the rain sensor or until the moisture is significant enough to trigger the switch to shut down the system.

Some devices claim to shut down the system immediately upon rain start to help reduce the public image of water waste (see Rain-Clik by Hunter).

Different types of Rain Sensors:
1. Mini-Clik

Photo of Mini-Clik

The Mini-Clik is a rain sensor manufactured by Hunter Industries Incorporated. According to the manufacturer, the Mini Clik operates with any automatic controller and works in this manner:

“Disks absorb water and expand proportionally to the amount of rain that fell (e.g., a small cloudburst would result in little absorption, a 6″ thunderstorm would lead to more absorption and expansion). As the moisture-laden disks expand, they eventually activate a switch that interrupts the circuit from the controller to the solenoid valves. Once dry, they contract and release the switch. Thus, Mini-Clik automatically resets without ever affecting your controller.”

You can view more information about the Mini-Clik including installation by following the link below:
http://www.hunterindustries.com/Products/Sensors/miniclikintro.html

2. Rain-Clik

Photo of Rain-Clik

The Rain-Clik is another rain sensor manufactured by Hunter Industries Incorporated.  This particular rain sensor is marketed with the angle that it provides a greater sense of water conservation since it shuts down a system immediately (within 2 to 3 minutes of rainfall onset). Their patented ‘Quick Response’ technology eliminates the need for water to accumulate prior to system shutting down.

Rain-Clik Mounting Options

You can view more information about Rain-Clik features and installation by following the link below:

http://www.hunterindustries.com/Products/Sensors/rainclikintro.html

3. Irritrol RainSensor Series

Photo of Irritrol RainSensor Wireless Series

Irritrol manufactures 3 models of rain sensor devices: wireless RainSensor (RS100), non-wireless RainSensor (RS500), and the wireless rain/freeze model (RSF1000). The wireless model provides constant communication between the transmitter and receiver connected to the sprinkler system controller.  All models are good for Residential, Light Commercial and Commercial uses.  According to Irritrol, the Rain/Freeze model helps reduce

“…damage to plants and danger to walkways caused by ice buildup by interrupting irrigation when the air temperature drops below a predetermined set point.”

For more information about Irritrol RainSensors click of the following link:

http://www.irritrol.com/controllers/controllers_rainsensors.html

If you would like to share your experience with rain sensors or know of a product on the market that is not displayed above then please feel free to comment.

(note: this article is provided for general information and consolidation of irrigation resources. We do not endorse any specific product in this article)