Hey guys, I'm currently working on a chemistry setup and we're building some protocols. We decided that every communication on the protocol between two devices will be in SI units. However, for a data descriptor I plan to use 4 bits per standard SI unit. This means that units for variables can go from -8 to 7. Now, I'm wondering if there is any measurable SI derived unit which has a higher power than 7 or lower than -8?. I can only get to -3 or +4, but that's it. Anyone suggestions? For instance, if you have pressure in hPa, this is kg * s^-2 * m^-1, the lowest is -2, highest is 1. Farad is kg^-1 m^-1 A^2 S^4, highest 4.