diff --git a/doc/user-manual/fpakc_UserManual.pdf b/doc/user-manual/fpakc_UserManual.pdf
index 37d8014..ef1494a 100644
Binary files a/doc/user-manual/fpakc_UserManual.pdf and b/doc/user-manual/fpakc_UserManual.pdf differ
diff --git a/doc/user-manual/fpakc_UserManual.tex b/doc/user-manual/fpakc_UserManual.tex
index fd48ed2..13be4cd 100644
--- a/doc/user-manual/fpakc_UserManual.tex
+++ b/doc/user-manual/fpakc_UserManual.tex
@@ -611,7 +611,7 @@ make
                                 \begin{itemize}
                                   \item \textbf{A}: Ampere.
                                   \item \textbf{Am2}: Ampere per square meter.
-                                                      This value will be multiplied by the square of the reference length to convert to A, it will not consider the surface area of injection.
+                                                      This value will be multiplied by the surface of injection.
                                   \item \textbf{sccm}: Standard cubic centimetre.
                                   \item \textbf{part/s}: Particles (real) per second.
                                 \end{itemize}
@@ -638,6 +638,11 @@ make
                             Temperature in each direction.
           \item \textbf{physicalSurface}: Integer.
                                           Identification of the edge in the mesh file.
+          \item \textbf{particlesPerEdge}: Integer.
+                                           Optional.
+                                           Number of particles to be injected by each edge in the numerical domain.
+                                           The weight of the particles for each edge will modified by the surface of the edge to ensure the right flux is injected.
+                                           If no value is provided, the number of particles to inject per edge will be calculated with the species weight and the surface of the edge respect to the total one.
         \end{itemize}        
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
       \subsection{reference}