I know that the maximum size of measured data files is approximately 30 MB, but can you give me an idea of how much data that is?

When recording 24 channels on the 24 dot model that's about 4.4 days. For 24 channels plus 24 MATH channels, it's approximately 2.2 days. 6 channels on a 6 dot model is approximately 5.7 days, and 4 channels on a 4-pen model is approximately 1.1 days.