The Kelvin Temperature Scale and Modern Means of Measuring the Temperature
The Kelvin Temperature Scale and Modern Means of Measuring the Temperature - раздел Образование, Part One THE PREDICATE About 200 Years Ago Scientists Noticed That A Sample Of Gas That Is Coolcd De...
About 200 years ago scientists noticed that a sample of gas that is coolcd decreases in volume in a regular way, and they saw that if the volume were to continue to dccrcasc in the same way, it would become zero at about -273°C. The conccpt was developed that this temperature -273°C (more accuratcly -273.15°C) is the minimum temperature, the absolute zero. A new temperature scalc was then devised by Lord Kelvin, a great British physicist (1824-1907). The Kelvin scale is defined in such a way as to permit the laws of thermodynamics to be expressed in a simple form.
The International Standard temperature scalc is the Kelvin scale with a new definition of the degree. The absolute zero is taken to be OK and the triple point of water is taken to be 273.1SK. (The triple point of water, the temperature at which pure liquid water, icc and water vapour are in equilibrium, will be discussed later.) With this definition of the degree, the boiling point of water at onc-atmosphcrc pressure is 373.15K and the freezing point of water saturated with air at onc-atmosphcrc pressure is 273.15K. Hence the SI Kelvin temperature is 273.15K greater than the ccntigradc temperature.
