Gas thermometer - a device for measuring temperature, based on the law of Charles .
Due to the fact that gas is used as a filler, the measurement range is increased. Such a thermometer can show a maximum temperature ranging from + 271 ° C to ~ 1000 ° C, depending on the gas used as a filler. This allows the use of gas thermometers to measure various hot substances. [one]
Principle of Operation
At the beginning of the XVIII century. In 1787, Charles found that the same heating of any gas leads to the same increase in pressure, if the volume remains constant. When the temperature changes on the Celsius scale, the dependence of the gas pressure at a constant volume is expressed by a linear law. And from this it follows that the gas pressure (at V = const) can be taken as a quantitative measure of temperature. By connecting the vessel in which the gas is located with a pressure gauge and calibrating the device, you can measure the temperature according to the pressure gauge .
Over a wide range of changes in gas concentrations and temperatures and low pressures, the temperature coefficient of pressure of different gases is approximately the same, therefore, the method of measuring temperature using a gas thermometer is little dependent on the properties of a particular substance used as a working fluid in the thermometer. The most accurate results are obtained if hydrogen or helium is used as the working fluid.
Gas thermometers are usually used only to check the thermometers of another device, more convenient in everyday use than gas ones.
Notes
- ↑ Thermometer. Types and device. Work and application. Features (rus.) (Neopr.) ? . Tech.Pribory.Ru (February 5, 2018). Date of treatment February 15, 2019.
Literature
- Gas thermometer - article from the Great Soviet Encyclopedia .
- Popov M.M. Thermometry and calorimetry. - 2 ed. - M. , 1954.
- Astrov D.N.