Ok, the coil resistance on the original meter is 2365Ω, and at full scale reading of 200µA, 0.473V (473mV) would be across the coil. If I wanted 0.000 100 V (100µV) resolution, that would require a minimum of 4 730 'steps,' which is greater than a 12-bit ADC can provide (4096). The Teensy 3.0...