It is not available as a standard check.
However, it can be implemented in a checklist with regular expressions, possibly tailored for the particular language pair because some languages need to have a space between the number and the UoM and other languages prefer to have no space between the number and the UoM. Also some clients/style guides or formats prefer to that the space between the number and the UoM is a non-breakable space.
So in your case, presuming the two languages/style guide prefer to have a regular space between the digit and the UoM, a checklist entry for the unit kg could be:
Source: "([0-9])=1 kg"
Target: -"@1 kg"
Seach Mode: Regular Expression