How is rainfall measured in mm?
Rainfall is typically measured using a rain gauge. It is expressed as the depth of water that collects on a flat surface, and is routinely measured with an accuracy up to 0.1 mm or 0.01 in. Rain gauges are usually placed at a uniform height above the ground, which may vary depending on the country. There are two types of gauge: 1. Storage Rain gauge: These are used to make daily or monthly measurements. 2. Recording Rain gauges: Can measure the intensity of rainfall using a ‘tipping bucket’ which will only tip when a certain volume of water is in it. An electrical switch can be used to record the tips.
