The imperial system is incomplete. It lacks units for anything from the last two centuries, like anything electricity-related: Electric current, voltage, power, capacity, resistance...
Information in something as old and common as a light bulb is in metric units in the USA. Luminous flux is measured in lumens (metric), power is measured in watts (metric), voltage is measured in volts (metric). Even Correlated Color Temperature is measured in Kelvin (metric) instead of Fahrenheit.
I guess americans don't use them or any electric devices in their daily lives enough, otherwise they would've already come up with their own, better units.
Last edited by Player2 - on 10 August 2020