The first measurements of rainfall were made known by the Greeks 500 years before Christ. One hundred years later in India, people use containers to collect rainwater and measure it.[4]​.

In both cases, measuring rainfall helped evaluate future crop yields.

In the book Artha-shastra that was used in the kingdom of Magadha, standards were established for each grain and the State granary had an indicator for fiscal purposes.[5]​.

In Palestine "Palestine (region)"), from the century BC. C. religious writings refer to the measurement of rainfall for agricultural needs.[4]​.

In 1441 in Korea, the first bronze rain gauge or alluvometer Cheugugi, was developed by scientist Jang Yeong-sil for use across a network that covers the entire country.[4][6]​.

In 1639, Benedetto Castelli, a disciple of Galileo, carried out the first precipitation measurements in Europe, to know the contribution of water from a rain event to Lake Trasimeno. There was a calibrated cylindrical glass container with a known amount of water and he saw the corresponding level in the bottle. Next, he placed the container in the rain, every hour he marked with a marker the level reached by the water.

In 1662, the Englishman Christopher Wren devised the first rain gauge with tilting buckets, which he associated, the following year, with a device that recorded various meteorological parameters such as air temperature, wind direction and precipitation.[4][7]​.

In 1670 Robert Hooke also used a tilting bucket rain gauge.[4]​

With the development of meteorology, the measurement of the different parameters of the atmosphere is resumed. Rain gauges are improved but the basic principles remain the same. In France, the meteorological association created by Urbain Le Verrier popularizes rain gauges known as: "Association".[4]​.

Several rain gauges and rain gauges have followed those with tipping buckets. We mention the float recording rain gauges, used since the 19th century, and the balance rain gauges.[4]​.

It is a simple indicator of fallen rain, consisting of a special cylindrical container "Cylinder (geometry)"), usually made of plastic, with a graduated scale. The height of the water that fills the jug is equivalent to the precipitation and is measured in millimeters (mm).

They consist of a funnel, which improves precision and collects the water in a graduated container, the instrument is placed at a certain height from the ground and an operator records the fallen water every 12 hours. With this type of instrument it is not possible to define the approximate hours in which it rained.

It consists of a rotating drum that rotates with a constant speed, this drum drags a graduated paper, on the abscissa the time is displayed and on the ordinate the height of the rainfall, which is recorded by a pen that moves vertically, powered by a float, marking the height of the rain on the paper. If it does not rain, the water level in the container remains constant and therefore the pen marks a straight horizontal line. When it starts to rain, the water that falls into the funnel, while the drum rotates, reaches the container and lifts the float, the boom will therefore mark a vertical elevation.

With this tool you can know the precipitation over time. When the pen reaches the top edge of the paper strip, it means that the level in the reservoir corresponds to the tip of the cannula, then an operation is activated to empty the container by lowering the float quickly, which corresponds to a vertical line on the graph.

This tool allows you to measure the average intensity of precipitation in a certain time interval:.

In reality, the intensity of rain is not constant, but varies over time, therefore it can be defined as instantaneous intensity of rain:.

The funnel leads the collected water to a small double triangular bucket, made of metal or plastic, with a hinge at its midpoint. It is a system whose balance varies depending on the amount of water in the buckets. The inversion generally occurs at 0.2 mm of precipitation, so every time 0.2 mm of rain falls the scale oscillates, emptying the full bucket, while the other begins to fill. Each time the double bucket moves, this movement is recorded on the paper strip that advances at a constant speed. At the end of the day, counting the number of times the bucket has moved, and multiplying it by the precipitation caused by its movement, we will obtain the precipitation that fell during the day or in a shorter time interval, with a precision of 0.2 mm.

Recently, the rain gauges available on the market are digital, recording the movement of the buckets through electronic systems that can be connected, for example, via radio "Radio (communication medium)"), with a central server that stores all the data collected in several rain gauges.

With these modern tools, the measurement can be carried out even in case of snow: if the funnel is equipped with a thermal resistance, it dissolves the snow.

The rain gauge is used to measure the amount of water there is in your national territory and where it is most useful is in the fields.

The first measurements of rainfall were made known by the Greeks 500 years before Christ. One hundred years later in India, people use containers to collect rainwater and measure it.[4]​.

In both cases, measuring rainfall helped evaluate future crop yields.

In the book Artha-shastra that was used in the kingdom of Magadha, standards were established for each grain and the State granary had an indicator for fiscal purposes.[5]​.

In Palestine "Palestine (region)"), from the century BC. C. religious writings refer to the measurement of rainfall for agricultural needs.[4]​.

In 1441 in Korea, the first bronze rain gauge or alluvometer Cheugugi, was developed by scientist Jang Yeong-sil for use across a network that covers the entire country.[4][6]​.

In 1639, Benedetto Castelli, a disciple of Galileo, carried out the first precipitation measurements in Europe, to know the contribution of water from a rain event to Lake Trasimeno. There was a calibrated cylindrical glass container with a known amount of water and he saw the corresponding level in the bottle. Next, he placed the container in the rain, every hour he marked with a marker the level reached by the water.

In 1662, the Englishman Christopher Wren devised the first rain gauge with tilting buckets, which he associated, the following year, with a device that recorded various meteorological parameters such as air temperature, wind direction and precipitation.[4][7]​.

In 1670 Robert Hooke also used a tilting bucket rain gauge.[4]​

With the development of meteorology, the measurement of the different parameters of the atmosphere is resumed. Rain gauges are improved but the basic principles remain the same. In France, the meteorological association created by Urbain Le Verrier popularizes rain gauges known as: "Association".[4]​.

Several rain gauges and rain gauges have followed those with tipping buckets. We mention the float recording rain gauges, used since the 19th century, and the balance rain gauges.[4]​.

It is a simple indicator of fallen rain, consisting of a special cylindrical container "Cylinder (geometry)"), usually made of plastic, with a graduated scale. The height of the water that fills the jug is equivalent to the precipitation and is measured in millimeters (mm).

They consist of a funnel, which improves precision and collects the water in a graduated container, the instrument is placed at a certain height from the ground and an operator records the fallen water every 12 hours. With this type of instrument it is not possible to define the approximate hours in which it rained.

It consists of a rotating drum that rotates with a constant speed, this drum drags a graduated paper, on the abscissa the time is displayed and on the ordinate the height of the rainfall, which is recorded by a pen that moves vertically, powered by a float, marking the height of the rain on the paper. If it does not rain, the water level in the container remains constant and therefore the pen marks a straight horizontal line. When it starts to rain, the water that falls into the funnel, while the drum rotates, reaches the container and lifts the float, the boom will therefore mark a vertical elevation.

With this tool you can know the precipitation over time. When the pen reaches the top edge of the paper strip, it means that the level in the reservoir corresponds to the tip of the cannula, then an operation is activated to empty the container by lowering the float quickly, which corresponds to a vertical line on the graph.

This tool allows you to measure the average intensity of precipitation in a certain time interval:.

In reality, the intensity of rain is not constant, but varies over time, therefore it can be defined as instantaneous intensity of rain:.

The funnel leads the collected water to a small double triangular bucket, made of metal or plastic, with a hinge at its midpoint. It is a system whose balance varies depending on the amount of water in the buckets. The inversion generally occurs at 0.2 mm of precipitation, so every time 0.2 mm of rain falls the scale oscillates, emptying the full bucket, while the other begins to fill. Each time the double bucket moves, this movement is recorded on the paper strip that advances at a constant speed. At the end of the day, counting the number of times the bucket has moved, and multiplying it by the precipitation caused by its movement, we will obtain the precipitation that fell during the day or in a shorter time interval, with a precision of 0.2 mm.

Recently, the rain gauges available on the market are digital, recording the movement of the buckets through electronic systems that can be connected, for example, via radio "Radio (communication medium)"), with a central server that stores all the data collected in several rain gauges.

With these modern tools, the measurement can be carried out even in case of snow: if the funnel is equipped with a thermal resistance, it dissolves the snow.

The rain gauge is used to measure the amount of water there is in your national territory and where it is most useful is in the fields.