# siunitx \celsius font

I am writing a lab manual and using \renewcommand{\familydefault}{\sfdefault} to set the font.

However, when using siunitx the\celsius unit does not change font. All other units (that I have so far used) use correct font, whereas \celsius seems to be cmr.

MWE

\documentclass{article}
\renewcommand{\familydefault}{\sfdefault}
\usepackage{siunitx}
\AtBeginDocument{\sisetup{math-rm=\mathsf, text-rm=\sffamily}}
\newcommand{\cc}{\cm\cubed}
\sisetup{range-phrase= --}
\begin{document}

\SI{250}{\cc} of solution were refluxed at \SI{73}{\celsius}.
A \SI{20}{\cc} aliquot of a solution of acetic acid was titrated against a standardised solution of NaOH (\SI{0.48}{\mole\per\deci\metre\cubed}. An average titre of \SI{15.3}{\cc} was required.

A solution was distilled ensuring only the fraction boiling from \SIrange{56}{58}{\celsius} was collected.

The fraction boiling in the range \SIrange{56}{58}{\degreeCelsius} was collected.%just to see if \degreeCelsius produces a different output to \celsius

\end{document}


I tried the following solution Can I make siunitx commands use serif fonts like the rest of the math in beamer? as can be seen in the 4th line of the MWE but doesn't work.

I also tried this suggestion (adapted to my needs) in the comments by Qrrbrbirlbel in Change fonts for units in siunitx (effectively the same as above.)

Is this just a bug as the correct font is selected for my other units?

Or is this a standard for \celsius?

• Until Joseph answers, a dirty trick is to use \let\mathrm\mathsf, \celsius is hardwired with a \mathrm – daleif Oct 14 '14 at 9:38
• One can reset the definition with math-celsius={{}^{\circ}\kern-\scriptspace \mathsf{C}} – Ulrike Fischer Oct 14 '14 at 9:49

As Ulrike comments, a change to math-celsius seems needed here
\sisetup{math-celsius = {}^{\circ}\kern-\scriptspace C}