TN-S earthing system

[MGIA]

Hi there.

I'm trying to find a good explanation to explain why the installation that i have to research has a TN-S earthing system.

I conducted several measurements, and they yielded a Zloop of 58 ohms for the L-PE measurement, 60 ohms for the L-N measurement, and 155 ohms for the L-L measurement. My professor mentioned that this already indicates it is a TN system. Why? To specifically indicate that it is a TN-S earthing system, can you simply demonstrate by stating that from the star point of the transformer, the PE and N have different sections?

If there is more information needed to help me, let me know.

Thank you in advance.https://ibb.co/R4bFWrH