Basic units of thermodynamics ~ MECHTECH GURU

Basic units of thermodynamics

Basic units of thermodynamics

Mass-------- kg.

Mole------ The mole is the amount of substance that contains as many atoms (or molecules)

as there are atoms in 0.012 kg of carbon-12. Length—m.

Time: second

SI unit of temperature is Kelvin (abbreviated as K). The Kelvin is defined as the fraction of 1/273.16 of the thermodynamic temperature of the triple point of water. The relation between Kelvin and Celsius temperature is K = C + 273.15 (The triple point of water is at 0.01 C).

Derived units: Force: 1 N = 1 kg m/s2, pressure 1 Pa = 1 N/m2, 1 bar = 10 Pa, 1 atm. = 101325 Pa. 

In thermodynamics we are concerned with absolute pressure.

 Gauge pressure = absolute pressure – atmospheric pressure.

 Ordinary vacuum gauge pressure = atmospheric pressure – absolute pressure.


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