diff --git a/src/apparatus: Fix "it's" -> "its" typo

diff --git a/src/apparatus/cantilever-calib.tex b/src/apparatus/cantilever-calib.tex
index 3b9c6c69ae14a73b5e40ba547cd2a8ae6e7c706f..af1d3f5aaf0441aa01c65e8563f5bdd91fe013d2 100644 (file)
--- a/src/apparatus/cantilever-calib.tex
+++ b/src/apparatus/cantilever-calib.tex
@@ -3,7 +3,7 @@
 
 In order to measure forces accurately with an AFM, it is important to
 measure the cantilever spring constant $\kappa$\index{$\kappa$}.  The
-force exerted on the cantilever can then be deduced from it's
+force exerted on the cantilever can then be deduced from its
 deflection via Hooke's law\index{Hooke's law}
 \begin{equation}
   F=-\kappa x \;.  \label{eq:hooke}