When I teach translation, I tell my students that they should learn well at least the most common measurement units.
Case in point from a translation I'm doing at the moment.
The source text already provides conversions, but at least in one instance they are wrong:
"...leaving about 1-2 inches (51-103 mm) of wire..."
If it is 1 to 2 inches, then the measurement in millimeters should be 25 to 51 mm: 51 to 103 mm is 2 to 4 inches.
I pointed out this conflict to my customer, who opted for "...2-4 inches (51-103 mm)..."
I believe all technical translators (especially those who edit other translators' work) should be able to spot such inconsistencies at a glance.
Pointing out such insidious errors is usually appreciated by customers, and tells them you are paying attention to what you are doing.