We were discussing Boyle’s law and Charles law in our recent post, we have also seen Avogadro’s law in our previous post and today we are going to understand here P-V-T surface in thermodynamics.

As we know very well that equation of state for an ideal gas deals with the relationship between pressure, volume and temperature. If we will plot above mentioned variables along x, y and z axis then we will have one surface which will indicate the equation of state i.e. PV=RT

And this surface will be termed as P-V-T surface in thermodynamics. Following figure displayed here indicates the P-V-T surface for an ideal gas.
Over this P-V-T surface, each point will indicate equilibrium state and each line will indicate the process.

P-V-T surface indicate lots of information at one glance, but practically in thermal engineering it will be quite easy to work with two dimensional diagram such as P-T, V-T and P-V diagrams.

### Reference:

Engineering thermodynamics, By R. K. Rajput
Engineering thermodynamics, By S. K. Som

We will see another important topic i.e. Stirling cycle and Ericsson cycle in the category of thermal engineering in our next posts.