Change the font size of siunitx output

Question

When writing numbers with units using the siunitx package, \SI{1064}{\um}, the numbers and units are noticeably smaller than the text, however the mu seems to be the correct size. I am using Verdana as the main text font and the default LaTeX font for maths. MiKTeX and compiled with LuaLaTeX.

MWE

\documentclass[10pt,a4paper]{article}
\usepackage{siunitx}
\usepackage{fontspec}
\defaultfontfeatures{Ligatures=TeX}
\setsansfont{Verdana} % Setting sans font
\renewcommand*{\familydefault}{\sfdefault} % Making sans serif font the default
\linespread{1.16} % Increasing the linespacing
\usepackage{unicode-math}

\begin{document} 
This is some text \SI{1064}{\um} m $m$
\end{document}

I try and scale using \defaultfontfeatures{Scale=MatchLowercase}

\documentclass[10pt,a4paper]{article} \usepackage{siunitx}
\usepackage{fontspec}
\defaultfontfeatures{Ligatures=TeX}
\setsansfont{Verdana} % Setting sans font
\renewcommand*{\familydefault}{\sfdefault} % Making sans serif font the default
\linespread{1.16}        % Increasing the linespacing
\usepackage{unicode-math}
\defaultfontfeatures{Scale=MatchLowercase}

\begin{document}
This is some text with scaling \SI{1064}{\um} m $m$
\end{document}}

The numbers and the m written in maths mode have become larger but the m in the units has not. I've tried \sisetup{detect-all} but that just changes everything written with \SI into Verdana which is not what I'm after. Is there a way to increase the size of the font in the units?

Answer 1

Your problem is that the math mode font is a different size to the body font. I've fix that by scaling, for example

\documentclass[10pt,a4paper]{article}
\usepackage{siunitx}
\usepackage{fontspec}
\defaultfontfeatures{Ligatures = TeX, Scale = MatchLowercase}
\setsansfont{Verdana} % Setting sans font
\renewcommand*{\familydefault}{\sfdefault} % Making sans serif font the default
\usepackage{unicode-math}
\begin{document} 
This is some text \qty{1064}{\um}.
\end{document}

Answer 2

My suggestion would be to load siunitx with the option mode=text. That way, the text font (here: Verdana) will be used automatically in \num and \unit directives.

% !TEX TS-program = lualatex
\documentclass{article} 

\usepackage{unicode-math}
\setmainfont{Verdana} % main font

\usepackage[mode=text]{siunitx}

\begin{document}
This is some text \dots\ \qty{1064}{\um}.
\end{document}

Answer 3

I initially marked @JosephWright's answer as the solution however this seemed to shrink the main font (Verdana) to match the maths font size.

So using his answer along with @Mico's comment on how to change the main maths font I have found a solution that seems to work:

\documentclass[10pt,a4paper]{article}
\usepackage{siunitx}
\usepackage{unicode-math}

\defaultfontfeatures{Ligatures=TeX}
\setsansfont{Verdana} % Setting sans font
\renewcommand*{\familydefault}{\sfdefault} % Making sans serif font the default
\setmathfont{Cambria Math}[Scale=MatchUppercase] % Setting the maths font and scaling to match Verdana size
\setmathrm{Cambria Math}[Scale=MatchUppercase] % Setting the upright maths font used by siunitx
\newfontfamily{\mufont}{Cambria Math} % Selecting the mu from the Cambria Math font...
\DeclareSIPrefix\micro{\ensuremath{\mufont μ}}{-6} % ...and the selecting it for use with siunitx and make it represent 10^-6

\begin{document}
This is some text \dots\ \qty{1064}{\um}.
\end{document}

I needed to set the upright maths font to Cambria Math and scale \setmathrm{Cambria Math}[Scale=MatchUppercase]