# Barometer

barometricaneroid barometerbarometersmercury barometeraneroidbarometric pressurebarometrybaroscopebarometric observationsbarometric reading
A barometer is a scientific instrument used to measure air pressure.wikipedia
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### Altimeter

altimetrybarometric altimeterpressure altimeter
Barometers and pressure altimeters (the most basic and common type of altimeter) are essentially the same instrument, but used for different purposes.
When a barometer is supplied with a nonlinear calibration so as to indicate altitude, the instrument is called a pressure altimeter or barometric altimeter.

### Evangelista Torricelli

TorricelliTorricelli, EvangelistaTorricellian
Although Evangelista Torricelli is universally credited with inventing the barometer in 1643, historical documentation also suggests Gasparo Berti, an Italian mathematician and astronomer, unintentionally built a water barometer sometime between 1640 and 1643. The concept that decreasing atmospheric pressure predicts stormy weather, postulated by Lucien Vidi, provides the theoretical basis for a weather prediction device called a "weather glass" or a "Goethe barometer" (named for Johann Wolfgang Von Goethe, the renowned German writer and polymath who developed a simple but effective weather ball barometer using the principles developed by Torricelli).
Evangelista Torricelli (, ; 15 October 160825 October 1647) was an Italian physicist and mathematician, best known for his invention of the barometer, but is also known for his advances in optics and work on the method of indivisibles.

### Siphon

syphoninverted siphoninverted siphons
On July 27, 1630, Giovanni Battista Baliani wrote a letter to Galileo Galilei explaining an experiment he had made in which a siphon, led over a hill about twenty-one meters high, failed to work.
Siphons were studied further in the 17th century, in the context of suction pumps (and the recently developed vacuum pumps), particularly with an eye to understanding the maximum height of pumps (and siphons) and the apparent vacuum at the top of early barometers.

### Altitude

high altitudealtitudeshigh-altitude
An altimeter is intended to be used at different levels matching the corresponding atmospheric pressure to the altitude, while a barometer is kept at the same level and measures subtle pressure changes caused by weather.
On the flight deck, the definitive instrument for measuring altitude is the pressure altimeter, which is an aneroid barometer with a front face indicating distance (feet or metres) instead of atmospheric pressure.

### Mercury (element)

mercuryquicksilverHg
He needed to use a liquid that was heavier than water, and from his previous association and suggestions by Galileo, he deduced by using mercury, a shorter tube could be used.
Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, mercury relays, fluorescent lamps and other devices, though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alternatives such as alcohol- or galinstan-filled glass thermometers and thermistor- or infrared-based electronic instruments.

### Gasparo Berti

Berti, Gasparo
Although Evangelista Torricelli is universally credited with inventing the barometer in 1643, historical documentation also suggests Gasparo Berti, an Italian mathematician and astronomer, unintentionally built a water barometer sometime between 1640 and 1643.
He is most famous today for his experiment in which he unknowingly created the first working barometer.

### Michelangelo Ricci

Ricci, Michelangelo
In a letter to Michelangelo Ricci in 1644 concerning the experiments, he wrote:
He played a significant part in the theoretical debates and experiments that led up to Torricelli's discovery of atmospheric pressure and invention of the mercury barometer.

### Puy de Dôme

Puy-de-DômePuy de DomePuy de Dôme mountain
Therefore, Pascal wrote to his brother-in-law, Florin Perier, who lived near a mountain called the Puy de Dome, asking him to perform a crucial experiment.
In 1648, Florin Périer, at the urging of Blaise Pascal, proved Evangelista Torricelli's theory that barometric observations were caused by the weight of air by measuring the height of a column of mercury at three elevations on Puy de Dôme.

### Blaise Pascal

PascalPascal, Blaise Pascal, Blaise
In 1646, Blaise Pascal along with Pierre Petit, had repeated and perfected Torricelli's experiment after hearing about it from Marin Mersenne, who himself had been shown the experiment by Torricelli toward the end of 1644.
By 1647, Pascal had learned of Evangelista Torricelli's experimentation with barometers.

### Barograph

Aneroid barographbarograph tracebarometrical clock
It is also used in meteorology, mostly in barographs and as a pressure instrument in radiosondes.
A barograph is a barometer that records the barometric pressure over time in graphical form.

### Measuring instrument

instrumentscientific instrumentinstruments
An aneroid barometer is an instrument used for measuring pressure as a method that does not involve liquid.
Barometer used to measure the atmospheric pressure.

### Torr

mmHgmm Hgmillimeters of mercury
A torr was originally defined as 1 mmHg.
The unit was named after Evangelista Torricelli, an Italian physicist and mathematician who discovered the principle of the barometer in 1644.

### Timex Expedition WS4

A barometer can also be found in smartphones such as the Samsung Galaxy Nexus, Samsung Galaxy S3-S6, Motorola Xoom, Apple iPhone 6 smartphones, and Timex Expedition WS4 smartwatch, based on MEMS and piezoresistive pressure-sensing technologies.
In addition to regular timekeeping, it features barometer, altimeter, thermometer, compass, and weather forecast functions.

### Meteorology

meteorologistmeteorologicalmeteorologists
It is also used in meteorology, mostly in barographs and as a pressure instrument in radiosondes.
In 1643, Evangelista Torricelli invented the mercury barometer.

### Johann Wolfgang von Goethe

GoetheJohann Wolfgang GoetheJ. W. Goethe
The concept that decreasing atmospheric pressure predicts stormy weather, postulated by Lucien Vidi, provides the theoretical basis for a weather prediction device called a "weather glass" or a "Goethe barometer" (named for Johann Wolfgang Von Goethe, the renowned German writer and polymath who developed a simple but effective weather ball barometer using the principles developed by Torricelli).
Goethe also popularized the Goethe barometer using a principle established by Torricelli.

### Smartwatch

smart watchsmartwatcheswatch phone
A barometer can also be found in smartphones such as the Samsung Galaxy Nexus, Samsung Galaxy S3-S6, Motorola Xoom, Apple iPhone 6 smartphones, and Timex Expedition WS4 smartwatch, based on MEMS and piezoresistive pressure-sensing technologies.
Peripheral devices may include digital cameras, thermometers, accelerometers, pedometers, heart rate monitors, altimeters, barometers, compasses, GPS receivers, tiny speakers, and microSD cards, which are recognized as storage devices by many other kinds of computers.

### Robert FitzRoy

FitzRoyCaptain FitzRoyFitzRoy, Robert
Fitzroy barometers combine the standard mercury barometer with a thermometer, as well as a guide of how to interpret pressure changes.
He directed the design and distribution of a type of barometer which, on his recommendation, was fixed at every port to be available to crews for consultation before setting out to sea.

### Lucien Vidi

The concept that decreasing atmospheric pressure predicts stormy weather, postulated by Lucien Vidi, provides the theoretical basis for a weather prediction device called a "weather glass" or a "Goethe barometer" (named for Johann Wolfgang Von Goethe, the renowned German writer and polymath who developed a simple but effective weather ball barometer using the principles developed by Torricelli).
In 1844 he invented the barograph, that is, a device to monitor pressure, a recording aneroid barometer.

### Jean Nicolas Fortin

Jean FortinFortin
Fortin barometers use a variable displacement mercury cistern, usually constructed with a thumbscrew pressing on a leather diaphragm bottom (V in the diagram).
Fortin is chiefly remembered for his design of barometer, now called a Fortin barometer, which he introduced in about 1800.

### Thermometer

thermometerstemperature sensortemperature
For this purpose a mercury thermometer is usually mounted on the instrument.
The above instruments suffered from the disadvantage that they were also barometers, i.e. sensitive to air pressure.

### Atmospheric pressure

barometric pressureair pressurepressure
A barometer is a scientific instrument used to measure air pressure.
Atmospheric pressure, sometimes also called barometric pressure (after the sensor), is the pressure within the atmosphere of Earth (or that of another planet).

### Otto von Guericke

von GuerickeGuericke, Otto VonOtto-von-Guericke
Inspired by Torricelli, Otto von Guericke on 5 December 1660 found that air pressure was unusually low and predicted a storm, which occurred the next day.
In the Experimenta Nova, Book III, Chapter 20, von Guericke reports on a barometer he had constructed and its application to weather forecasting.

### Bert Bolle Barometer

Rustenhoven
Bert Bolle Barometer
At over 12.5 metres tall, it is recognized as the largest barometer in the world by The International Guinness Book of Records.

### Weather station

meteorological stationweather stationspersonal weather station
Its dial is rotated so that the current atmospheric pressure from a known accurate and nearby barometer (such as the local weather station) is displayed.
Barometer for measuring atmospheric pressure

### Microbarometer

microbarograph
Microbarometer
Microbarometers are sensitive barometers that can measure air pressure with high precision.