View attachment 80331
Here's the procedure
The coupling on the left is a generator, on the right is a steam turbine rotor.
You place a mag-base indicator on either side of the coupling and it reads the misalignment of the outer rim,
as you rotate the two couplings at the same time, keeping them aligned together.
Every 90 degrees of rotation, you measure the gap between the couplings at 4 points, 0 degrees, 90 ,180 and 270.
In my industry, it's called the "16 point Coupling Check".
I learned that in 1980.
Please stick to what you know and don't challenge people who will embarrass you about what you don't know !