diff --git a/Running-the-PAS.md b/Running-the-PAS.md
index 3988964..4615fe6 100644
--- a/Running-the-PAS.md
+++ b/Running-the-PAS.md
@@ -45,4 +45,12 @@ A separate script performs a frequency sweep and can be run prior to the start o
      julia ~/pas-sweep.jl
     ```
 
-*Currently the data must be fit manually after acquisition.  Typically looking by eye in a spreadsheet program is close enough for the 3-λ system.*
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+*Currently the data must be fit manually after acquisition.  Typically looking by eye in a spreadsheet program is close enough for the 3-λ system.*
+
+# Shut Down the PAS
+
+1. Ensure the PAS has been purged with nitrogen or zero air.
+
+2. Turn off or unplug the 12 V supply.
+
+3. In the terminal on the host computer, press `CTRL + C` to stop the real-time plots.  Sometimes you may have to press this more than once in rapid succession to stop the program.  You should see the Julia REPL prompt (`julia >`) when done.  Some error messages are normal upon exit.  The plots window can be left open or closed by clicking the 'x' in the upper right corner.
\ No newline at end of file