siunitx: µ doesn't work

Question

I'm using TeXnicCenter for Windows (7) and I'm a bloody beginner in everything that concerns LaTeX. I'm using the siunitx package for mathematical formulas and it works just fine... with one exception. The \micro (e.g. \si{\micro}) command doesn't work! It simply doesn't show the µ in the PDF file. I've tried to use \u as well without success. Does anybody know what the error could be?

Answer 1

I’ll throw this in here, as my search for a solution led me here, but my problem was another one.

Using XeTeX and Latin Modern, I found that the greek letter μ does not work. However, the Unicode micro sign μ does work.

Knowing that, I added \sisetup{math-micro=\text{µ},text-micro=µ}, and now all seems well.

To clarify, use

µ
MICRO SIGN
Unicode: U+00B5, UTF-8: C2 B5

and not

μ
GREEK SMALL LETTER MU
Unicode: U+03BC, UTF-8: CE BC

for great justice.

MWE for my setup (XeTeX on OS X):

\documentclass{standalone}
\usepackage{fontspec}
\usepackage{siunitx}
% Note that the sign must be
%  µ
%  MICRO SIGN
%  Unicode: U+00B5, UTF-8: C2 B5
% and \emph{not}
%  μ
%  GREEK SMALL LETTER MU
%  Unicode: U+03BC, UTF-8: CE BC
\sisetup{math-micro=\text{µ},text-micro=µ}

\begin{document}
Now you can \si\micro\ all the things.
\end{document}

Answer 2

Here is a MWE which compiles fine, using the command @daleif suggested

\documentclass[a4paper,final]{article}

\usepackage[T1]{fontenc}
\usepackage[]{lmodern}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}

\usepackage[]{siunitx}
\usepackage{textcomp}

\begin{document}

  Greek letter \textmu{} in normal text.
  Greek letter µ in normal text.
  The unit for viscosity is \si{\micro\pascal}.
  Just the \si{\micro} is not a SI unit but it works anyway.
  Some number with unit \SI{51}{\micro\metre} lorem ipsum.
  A number with unit in a formula $\SI{123}{\micro\metre}$ dolor sit amet.

\end{document}

As shown in the example, use \si for just units and capital \SI for a value-with-unit-combination.
And if you want a plain µ in the text, you could also try the command \textmu which is made available by the package \usepackage{textcomp}

Answer 3

Depending on which engine and encoding you use, you can just write a literal μ. Or you can typeset it in math mode as a variable $\mu$. It depends on what use the μ has in your document.

If it is a quantifier then add the corresponding unit as daleif already pointed out in the comment.

Answer 4

Another solution is through the use of the "Babel" package + "Lualatex" as follows, this method defines the symbol as a greek letter: This answer is in accordance with the solution proposed by David Purton: Biblatex usage for multiple languages in same citation

\documentclass[a4paper,12pt,twoside]{book}
\usepackage[bidi=basic,layout=lists.tabular]{babel}
% Define used languages
\babelprovide[import=en,language=Default]{english} % default language
\babelprovide[import=el]{polutonikogreek}
%Define fonts to be used corressponding to each language (Ordinary ttf fonts installed on your system)
\babelfont[english]{rm}{Times New Roman}
\babelfont[polutonikogreek]{rm}[Language=Default]{Palatino Linotype}

\begin{document}

\foreignlanguage{polutonikogreek}{μ} \\
OR\\

\begin{otherlanguage}{polutonikogreek}
μ \\
\end{otherlanguage}

OR\\
%The method below is not preferred as it only uses the font without language definition, also it can be used with babel or polyglyossia package:

\begingroup
   \newfontfamily\myfont[Numbers=OldStyle]{Palatino Linotype}
{\myfont μ}
\endgroup
OR\\
\selectlanguage{polutonikogreek}
μ
\end{document}