T-S Diagram – ts diagram – t-s diagrams – TS diagrams – P-V diagram – pv diagram – P-V diagrams. Temperature entropy diagram. Pressure volume diagram. Temperature entropy chart. Pressure volume chart. A temperature entropy diagram, or T-s diagram, is used to show in thermodynamics to show changes to temperature and entropy during a thermodynamic cycle or process. T-S Graph. T-S Diagram is shown in the image below.