Rain gauges are the most common tool for measuring rain, but how do they actually work? What are some other ways we measure precipitation?
Reading a rain gauge is simple. We can look at the measurement marks on the side of a rain-capturing device, and find the level of water collected from a passing storm. Depending on what system is used where we live, we can read inches or millimeters and say how much rain has fallen. But the device collects a volume of liquid, doesn’t it? Why do rain gauges measure rain in millimeters or inches, which are units of length, instead of in pints or liters, which are units of volume?