TODO how does basing it on the elementary charge help at all? Can we count individual electrons going through a wire? https://www.nist.gov/si-redefinition/ampere/ampere-quantum-metrology-triangle by the NIST explains that is it basically due to the following two quantized solid-state physics phenomena/experiments that allows for extremelly precise measurements of the elementary charge:

- quantum Hall effect, which has discrete resistances of type:
for integer vallues of $Î½$.$R_{xy}=I_{channel}V_{Hall}â€‹=e_{2}Î½hâ€‹$
- Josephson effect, which provides the Josephson constant which equals:
$K_{J}=h2eâ€‹$

- International System of Units | 47, 276, 15
- Physics | 276, 33k, 581
- Natural science | 0, 41k, 934
- Science | 0, 45k, 1k
- Ciro Santilli's Homepage | 238, 163k, 3k

- Applications of Josephson Junctions | 63, 101, 1
- Quantum Hall effect | 74, 74, 3