Types of Rain Gauges

Rain gauges are mainly used to measure rainfall, and they work in three different ways. The three main types of rain gauges are standard rain gauges, tip bucket rain gauges, and weighing rain gauges. Although the basic operation of rain gauges is generally no different from those of these major types of rain sensors, aspects such as how they are set up and how data is transmitted can be further distinguished.

Standard Rain Gauge

Recording rainfall using a standard rain gauge or funnel rain gauge is usually done manually. These meters work by collecting rainfall through a funnel-shaped collector attached to a measuring tube. The pipes are typically eight inches long and have been in use for more than a century, according to the National Weather Service office in Spokane. The diameter of the collector is 10 times that of the tube; So a rain gauge works by magnifying the liquid by a factor of 10. Amplifying rain in this way can be accurate to one hundredth of an inch. The amount in excess of the tube capacity is captured in the enclosure of the meter, allowing the recorder to pour the liquid out of the tube and fill it as needed.

Tipping Bucket Rain Gauge

Operation of a tipping bucket rain gauge is quite different from the standard gauge. The receiving funnel leads to one of two small buckets. Filling of one bucket occurs at one-hundredth of an inch. The result is a “tipping” of the liquid into the outer shell of the gauge, triggering the second bucket to takes it place. The process then repeats itself. Allowing for precise measurement of rainfall intensity and amount, this gauge has become standard for wireless weather stations. According to “Essentials of Meteorology” by C. Donald Ahrens, “Each time a bucket tips, an electric contact is made, causing a pen to register a mark. …” Today, wireless digital tipping bucket gauges are very common, but they still use the same basic technology.

Weighing Rain Gauge

According to the Albany, New York National Weather Service office, the universal weighing rain gauge is optimal for climatology use. This is because of a vacuum that accounts for the effects of wind, allowing more rain to enter the gauge. These gauges are very precise in measuring rainfall intensity as the weighing mechanism at the bottom of the collector can be used to measure depth and time simultaneously. Recording is carried out much in the same way as the older versions of the tipping bucket gauges.