SI prefixes (just because you can, doesn't mean you should)

  • Tue 24 October 2017
  • misc

Milli-rant here.

In recent years, particularly in electronics, I've noticed a tendency to use every SI prefix available. For instance, a 0.1 µF power rail decoupling capacitor might be quoted as 100 nF.

This is a good way to end up with off-by-three-orders-of-magnitude problems. Use the traditionally scaled units that humans are used to dealing in and ignore the interstitial ones. In the case of capacitors that would be µF and pF (or µµF if you remember the days when men were men and megahertz were megacycles).

Stated another way, I don't say that I drove my car 20 Mm (megameters) last year; I drove it 20,000 km. While technically correct, the best kind of correct, it involves unnecessary mental gyrations.

The soda can from which I am drinking says 355 mL on the side. Not 3.55 dL. Case made?