Hi Naaman.

You get can the pressures experientally via pressure gauges or via mathematical models using thermodynamic/gas law principles.

I am not sure if this addresses your question.

Another theoretical approach is measuring temperatures at the respective points and the converting it to pressures via the property tables of refrigerants.

Matthew Schouw Thank you for your answer. Yes, the article itself refers to Kland relations and I understood to some extent how to calculate the characteristics of the working fluid at the input and output of the cycle components.

Another alternative is to look at published data(maybe a thesis) on a similar compressor (with your respective refrigerant) and develop polynomial equations /curve fitting of the data.

But otherwise experiments is king.

Otherwise check this publication below(not my own) . It will definitely assist.

Let me know