pluviometer

A pluviometer, commonly known as a rain gauge, is an instrument used to measure precipitation at a specific location. It collects liquid water from rain or melted snow in a calibrated container, and the rainfall depth is expressed in units such as millimeters or inches. The depth is determined by dividing the collected water volume by the known catchment area of the gauge.

There are manual and automatic forms. Manual gauges are simple cylinders or collectors that require periodic reading and emptying. Automatic gauges include tipping-bucket devices, weighing gauges, and optical or acoustic gauges that continuously record rainfall and transmit data. Tipping-bucket gauges register small increments of rainfall each time a bucket tips, while weighing gauges convert the weight of collected precipitation to depth.

Positioning and accuracy are important. Gauges should be placed in an open, unobstructed exposure away from buildings, downspouts, and trees to minimize wind distortion, splashing, and splatter. They should be sheltered from direct sunlight and maintained to reduce evaporation and contamination. Calibration and routine maintenance are essential for reliable measurements, including clearing debris and checking for leaks or misreadings in automatic systems.

Applications include meteorological stations, hydrological networks, climate research, and agricultural planning. Rainfall data from pluviometers support daily, monthly, and annual totals, trend analyses, flood forecasting, and water-resource management. The term pluviometer is one of several synonyms; many contexts prefer rain gauge, while in some languages or regions the term pluviometry or pluviometry gauge may be used.