This tipping bucket rain gauge has a magnetic reed switch that closes momentarily each time the gauge measures 0.011" (0.2794 mm) of rain.
The 9 foot (3 meter) cable terminates in an RJ11 modular plug, and can easily be extended using a common telephone extension cable.
The gauge can be easily connected to an Arduino, Rapberry Pi, or any microcontroller. Commonly a pull-up resistor (4.7k ohms is typical) will be used to pull the input pin high, and the other side of the gauge's switch will be connected to ground, pulling the pin low each time the switch closes.
This is the same gauge used on our ADS-WS1 weather station and the 80422 sensor assembly and can be used as a replacement part in either of those products.
Dimensions are 4.75" x 2.38" x 3", excluding the mounting tabs. The mounting tabs extend 0.6" and have 0.168" diameter holes on 5.35" centers.
We recommend mounting this gauge to a stable base, such as a roof or the top of a fence. If the gauge is free to sway in the wind on a tall mast, its movement may cause false readings.
Adding wire mesh to the drain holes on the bottom can help keep out spiders and insects that may interfere with the operation of the mechanism.