[O] Writing microsecond time unit

[Xavier Garrido]

Dear Orgers,

I would like to do something very simple such as writing microsecond 
unit but I fail. I try different way (\mu\nbsp s, $\mu$s, \mu s) but 
always get a whitespace between the µ symbol and the second symbol. The 
only working version is $\mu\text{s}$ which gives me a pure LaTeX code 
which is find for LaTeX to pdf export but is quite annoying when I 
export to html. Is there a simple way to use the symbol µ glued to a 's' ?

Thanks in advance,
Xavier