I have problems with the combination of using siunitx and displaying upright partial derivative symbols using:
\usepackage[partialup]{kpfonts}
The unit prefix µ is not displayed using this code:
\documentclass[preview]{standalone}
\usepackage{fontspec}
\usepackage[T1]{fontenc}
\usepackage[partialup]{kpfonts}
\usepackage{siunitx}
\begin{document}
\SI{1}{\micro\meter}
\end{document}
Adding the line
\sisetup{math-micro=\text{µ},text-micro=µ}
as mentioned on this board will display a ţ instead of a µ.
I've no idea how to solve that problem and would aprecciate your help.
siunitx
is looking for a symbol that does not exist, as with these Unicode engines it goes with 'just use a µ' as the standard position. (The ţ is a µ, or at least it's in that slot in the T1-encoded text font you are using.)