Editing Guide to technical writing (section)

==Units==
* Always insert physical units after a number.
* Always insert a space between a number and the units. Do this with a tilde (~) in LaTeX.
* Exceptions are that there is no space between a number and the % sign and the °C or ° signs. There are some rare journals whose style is to have a space here and you should then obey that.  But for your thesis and most journals there is no space.
* Units are always in upright font, so write them outside the math environment.