1 files changed, 67 insertions, 8 deletions
diff --git a/acquisition/chapter.tex b/acquisition/chapter.tex
index ff6bcdf..78b4199 100644
--- a/acquisition/chapter.tex
+++ b/acquisition/chapter.tex
@@ -734,21 +734,80 @@ Each motor can be independently set and homed.  %
 \clearpage
 \section{Sensors (devices)} \label{aqn:sec:sensors}  % ============================================
 
-Sensors are...
+Sensors are the kind of things that actually measure data.  %
+In spectroscopy these can be photodiodes, array detectors, photo-multiplier tubes etc.  %
+In this section I describe the strategy that PyCMDS uses to represent sensors.  %
+
+\subsection{The DAQ card}  % ----------------------------------------------------------------------
+
+The National Instruments PCI-6251 card is capable of eight analog inputs and 1 million samples per
+second (one sample per microsecond).  %
+Both instruments operate at 1 KHz, so that leaves 1000 samples per shot.  %
+It is important to be able to configure all of the timings within each shot.  %
+
+\autoref{aqn:fig:samples} shows the GUI designed to control the sample level timing of the NI
+PCI-6251 card.  %
+All 1000 samples for the current shot are displayed in the large central plot.  %
+Users may allocate regions of samples to be assigned to particular channels.  %
+A second region may be allocated for explicit baseline subtraction.  %
+For things like PMTs, make sure these two regions are the same size.  % BJT: explain why
+For each region, a simple processing method is applied before the baseline is (optionally)
+subtracted and the signal is (optionally) inverted.  %
+All of this results in a single processed value for each channel on each shot.  %
+Users may also allocate exactly one sample for chopper monitoring.  %
+
+\autoref{aqn:fig:shots} is a screenshot of the shots GUI.  %
+Only one channel is shown, chosen by the pull down menu on the right hand side.  %
+Each point is one processed value from all of the samples designated for that particular shot.  %
+Because this instrument is using dual chopping at this time, only one out of four shots has a large
+amount of light, so most shots are near zero in \autoref{aqn:fig:shots}.  %
+
+[SHOTS PROCESSING]
+
+% BJT: more about the power of digital processing
+%Old boxcar: 300 ns window, ~10 micosecond delay. Onset of saturation ~2 V.
 
-For DAQ cards, shots and samples...
+\begin{landscape}
+\begin{figure}
+  \includegraphics[width=9in]{"acquisition/screenshots/003"}
+  \caption{
+    CAPTION TODO
+  }
+  \label{aqn:fig:samples}
+\end{figure}
+\end{landscape}
 
-Power of digital processing...
+\begin{landscape}
+\begin{figure}
+  \includegraphics[width=9in]{"acquisition/screenshots/002"}
+  \caption{
+    CAPTION TODO
+  }
+  \label{aqn:fig:shots}
+\end{figure}
+\end{landscape}
 
-Old boxcar: 300 ns window, ~10 micosecond delay. Onset of saturation ~2 V.
+\begin{figure}
+  \caption{
+    TODO: SHOTS PROCESSING SCRIPT
+  }
+\end{figure}
 
-% TODO: screenshots
+\subsection{Multidimensional sensors}  % ----------------------------------------------------------
 
-\subsection{Sensors as axes}  % -------------------------------------------------------------------
+Sensors need not be single valued at each hardware coordinate.  %
+Sometimes, a sensor returns an entire array of information.  %
+In cases like these, PyCMDS expands the dimensionality of the scan to accommodate the many-valued
+sensor.  %
 
-% TODO: equation from Skye
+For example, consider \autoref{aqn:fig:array_as_axis}.  %
+This simple tune test was taken with an array detector, rather than using a scanning
+monochromator.  %
+Although only one piece of hardware was scanned, the data is considered to be
+\emph{two}-dimensional, with the second dimension being $\bar{\nu}_a$, the differential color axis
+for the array vs the OPA setpoint.  %
 
-% TODO: poweramp tune test  (see darien slack)
+[EQUATION]
 
 \begin{figure}
   \includegraphics[scale=0.5]{"acquisition/tune_test"}