apparatus/afm.tex: Add range of the 2253E piezo

DAC range (V_dac) * gain (V_piezo / V_dac) * sensitivity (m / V_piezo):

  >>> 20 * 20 * 8.8e-09    # z axis
  3.5199999999999998e-06
  >>> 20 * 20 * 4.16e-09   # x axis
  1.6639999999999999e-06

diff --git a/src/apparatus/afm.tex b/src/apparatus/afm.tex
index 1940a8f1b50e6c6f6f8dbd6b8d4321772547f041..87cfd22de994cf592e3e1a28284cfd20466d1c9c 100644 (file)
--- a/src/apparatus/afm.tex
+++ b/src/apparatus/afm.tex
@@ -21,9 +21,9 @@ The substrate is mounted in a fluid cell\citep{drake89,radmacher92} on
 a three dimensional piezoelectric actuator so that the tip may be
 positioned on the surface with sub-nanometer resolution (although
 signal drift and piezo hysteresis can cause larger errors in the
-positioning accuracy).  Our tubular piezo has a range of TODO in the
-horizontal directions and a range of TODO in the vertical
-(\cref{fig:piezo-schematic}).
+positioning accuracy).  Our tubular piezo has a range of
+$1.6\U{$\mu$m}$ in the horizontal directions and a range of
+$3.5\U{$\mu$m}$ in the vertical (\cref{fig:piezo-schematic}).
 
 \begin{figure}
   \begin{center}