A mercury barometer is used to calibrate and check aneroid barometers . Calibration can be, for example, in terms of atmospheric pressure or altitude above sea level. The concept of altitude above sea level, based on barometric pressure, is used to create one type of aircraft altimeter.
What is mercury barometer used for?
A mercury barometer is an instrument used to measure atmospheric pressure in a certain location and has a vertical glass tube closed at the top sitting in an open mercury-filled basin at the bottom. Mercury in the tube adjusts until the weight of it balances the atmospheric force exerted on the reservoir.
For what use barometer is used?
A barometer is a scientific instrument used to measure atmospheric pressure, also called barometric pressure . The atmosphere is the layers of air wrapped around the Earth. That air has a weight and presses against everything it touches as gravity pulls it to Earth. Barometers measure this pressure.
What is an mercury barometer?
A mercury barometer is a barometer with a column of mercury whose height varies according to the atmospheric (barometric) pressure. A barometer is an instrument for measuring atmospheric pressure , which is used in forecasting the weather.
What is the principle of a mercury barometer?
Thus, in a barometer, one end is sealed to prevent air from disturbing the scale and measures. Therefore, a Mercury Barometer works on the principle of balancing the atmospheric pressure with the volume of mercury present in the device .
Why is water not suitable to be used in a barometer?
Water is not a suitable barometric liquid because: ... Water barometer will support 10.4m of water at sea level . It is impractical to have such a long tube.
What is the basic principle of barometer?
Thus, in a barometer, one end is sealed to prevent air from disturbing the scale and measures. Therefore, a Mercury Barometer works on the principle of balancing the atmospheric pressure with the volume of mercury present in the device .
What is barometer with diagram?
Simple barometer – diagram
An inverted glass tube is standing in the bath of mercury and air pressure is exerted on the surface of mercury. The pressure at the top of the mercury column is zero as there is a vacuum there. Due to atmospheric pressure we can see some raise in glass tube.
What is the most accurate barometer?
- BTMETER Digital Barometer.
- ThermoPro Digital Barometer.
- ThermoPro TP65A Digital Barometer.
- AcuRite 00795A2 Galileo Glass Globe Barometer.
- Lily’s Home Analog Weather Station Barometer.
How do you read a mercury barometer?
There are two forms of mercury barometer; stick (you read the mercury height by looking directly at the top of the column inside the glass tube, and compare it to a scale of inches printed or engraved beside the column), and dial, also known as wheel or banjo (you read from a hand pointing to numbers on a dial, ...
Is it illegal to have a mercury thermometer?
Those days have passed. Since 2001, 20 states have banned mercury “fever thermometers” for medical use , and regulations tighten every year. ... But as of today the federal government has more or less killed the mercury thermometer in the United States—NIST has announced it will no longer calibrate mercury thermometers.
Why water is not used in mercury barometer?
Explain why water cannot be used in place of mercury in a barometer? The atmospheric pressure at sea level = 76cm of Hg = 1.013×10 5 Pascal. That is, if water is used in barometer tube instead of mercury, the length of the tube must be greater than 10.326 cm . ... So, we cannot replace mercury by water in the barometer.
Is pressure greater in salt water?
Salt water is denser than fresh water. Pressure will be greater beneath the salt water than the fresh water at the same depth. ... The pressure on an object submerged in a fluid does not depend on the surface area of the fluid or object.
Why is mercury preferred over water in a barometer?
Mercury is used in barometers and not water. This is because the high density of mercury gives a reasonable height of the column to measure atmospheric pressure . While a barometer using water, for instance, would need to be 13.6 times higher column length than a mercury barometer to obtain the same pressure difference.
