How does a rain gauge work?

The most common rain gauge that is used today by forecasters and airports around the world was created over 100 years ago. The rain gauge consists three main parts: a funnel, a measuring tube, and an overflow tube.  They also typically come with a bracket to attach the rain gauge to. The funnel is connected to the top of the measuring tube. The measuring tube is located inside of the outside overflow tube. The funnel directs the rain down into the measuring tube and magnifies it 10 times. The smaller measuring tube on the inside that is used to exaggerate the height of the water, allows for a more precise precipitation measurement. This exaggeration allows for meteorologists to make very accurate measurements up to one-hundredth of an inch. The inside tube measures up to an inch of water. If rainfall exceeds 1 inch, the water will overflow into the outer cylinder.