What is a gas thermometer?

What is a gas thermometer?

A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. It consists of a bulb connected by a capillary tube to a manometer. The bulb is filled with a gas such that the volume of the gas in the bulb remains constant.

Can gas be used in thermometer?

In gas thermometers, the pressure rise connected with a temperature increase is used for measuring the temperature! In gas filled temperature gauges (also called gas thermometers or gas-in-metal thermometers), a gas is used as the thermometric fluid instead of an liquid as it is in liquid-in-metal thermometers.

What is gas thermometer write its characteristics?

[¦gas thər′mäm·əd·ər] (engineering) A device to measure temperature by measuring the pressure exerted by a definite amount of gas enclosed in a constant volume; the gas (preferably hydrogen or helium) is enclosed in a glass or fused-quartz bulb connected to a mercury manometer.

Why is a gas thermometer?

Gas Thermometer. Gas thermometry reduces temperature measurement (from helium temperatures to 1063°C) to measurement of pressure or a gas volume in a closed vessel (under certain conditions) followed by temperature calculation using the measurement results and the ideal gas laws.

What is a gas thermometer used for?

a device for measuring temperature by observing the change in either pressure or volume of an enclosed gas.

Which gas is used in a gas thermometer?

For technical measurements, use is made of filled-system gas thermometers working at temperatures from –150 to 600°C. At a temperature up to 600°C nitrogen is used as a working gas, while above 600°C argon is used.

Which substance is used in the thermometer?

Mercury is one of the most familiar materials used in liquid thermometers. Other liquids, such as kerosene or ethanol, may also be used in these types of thermometers.

Why is a gas chosen as the standard thermometric substance?

But with experiments, it is found that the minimum variation is observed among the gas thermometers. Therefore gas is chosen as a standard thermometric substance.

What is the purpose of a gas thermometer experiment?

Gas Thermometry gas-thermometry The purpose of the Gas Thermometry experiment is to construct a temperature scale and determine the absolute zero temperature. This experiment demonstrates the temperature dependency of the pressure of a constant gas volume.

What is a gas thermometer and how does it work?

These thermometers work on the principle that pressure varies as a function of temperature, according to the gas law. The measuring system of gas thermometers consists of a capillary tube and a tubular coil. A temperature variation acting on the sensor proportionately alters the pressure of the gas contained within it.

Which is the best type of gas thermometer to use?

Depending on the character of gas transition from 1-to-2 state, three gas thermometers are distinguished: those of constant volume, constant pressure and constant temperature. A constant-volume gas thermometer is used at low temperatures (typically with helium as a working substance) and possesses the highest sensitivity.

When to use a constant volume gas thermometer?

A constant-volume gas thermometer is used at low temperatures (typically with helium as a working substance) and possesses the highest sensitivity. At high temperatures, when gas desorption on reservoir walls becomes pronounced and helium penetrates through the walls, gas thermometers of other design are used with nitrogen as a working substance.

Can a liquid thermometer be used to measure temperature?

Mercury and other liquid thermometers cannot be used to measure temperatures in kelvins. Kelvin thermometers are usually electric devices that can record tiny variations in radiation. These variations would not be visible and may not change air pressure enough to raise the level of mercury in a liquid thermometer.

How is the scale of a gas thermometer obtained?

The scale of a filled-system gas thermometer (T = f (p)) is obtained using a knowledge of a volume of the instrument components. For this, corrections are made for the gas nonideal state, thermal expansion of the bulb and capillary, temperature variation, etc.