What I'm wondering is if the sensors read X% of the current, so if I'm pulling 75% on a 20A circuit (so 15A), will the 20A read 15A and a 30 read 22.5 (b/c 75% of 30A is 22.5A)? I'm guessing it won't do this, but want to be certain. I'm suspecting that the reading would just be less accurate like instead of reading 15.15 amps, it might read 15.2, or 5.56 vs 5.6 - because a larger scale is being used to measure a smaller amount of current.

Is this correct? Will I be alright with the larger sensors for the extra's that I want to ensure will cover the largest circuit but also be able to use them on smaller ones?