Calculate EMVA1288 temporal dark noise
I'm happy to see that other people are working with EMVA1288 as i'm one of the authors and test equipment manufacturer.

Your calculation is incorrect. The total noise is not the dark temporal noise, you need to get rid of the fixed pattern noise.

In EMVA1288, we do this by accumulating images in large quantities to separate the fixed noise and the temporal noise. This is quite well explained in the standard. If you do not exactly follow the procedures in the standard then you will not be compliant. There are more details to come about this compliance in future versions of the standard.