Finally, the wind vane reports wind direction as a voltage which is produced by the combination of resistors inside the sensor. A wind speed of 1.492 MPH produces a switch closure once per second. The anemometer (wind speed meter) encodes the wind speed by simply closing a switch which each rotation. The rain gauge is a self-emptying bucket-type rain gauge which activates a momentary button closure for each 0.011' of rain that are collected. The positive side of this is that the sensors are easy to interpret: None of the sensors in this kit contain active electronics, instead they use sealed magnetic reed switches and magnets so you'll need to source a voltage to take any measurements. This kit represents the three core components of weather measurement: wind speed, wind direction and rainfall. When you're measuring weather, however, you need some pretty specialized sensors.

Whether you're an agriculturalist, a professional meteorologist or a weather hobbyist, building your own weather station can be a really rewarding project.

Electronic rain meter