I am trying to reproduce the look of the micro symbol in the siunitx
documentation; see for instance the following picture:

However, when compiling the following code:
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{textcomp}
\usepackage{siunitx}
\begin{document}
\SI{15}{\micro\metre}
\end{document}
the mu comes out with serif as in the following picture:

I suppose there is a font issue here but I could find how to solve it by reading the siunitx documentation.
lmodernwithmathpazo. – Torbjørn T. Feb 28 '13 at 18:50