\documentclass{article}% Manuel Luque
\usepackage{pstricks,multido}%
\input{random.tex} % From Donald Arseneau (on macros/generic on CTAN)
\SpecialCoor
\def\manometre{%
  \pscircle[doubleline=true,fillstyle=solid](0,0){1}
  \psarc(0,0){0.65}{-60}{240}
  \multido{\i=-60+30}{11}{\psline(0.65;\i)(0.45;\i)}
  \psline[arrowscale=2,linewidth=2\pslinewidth]{->}(0.5;-70)(0.65;110)
  \pscircle[fillstyle=solid]{0.1}%
}
% idée empruntée à Denis Girou
\newdimen\Xd
\newdimen\Yd
\def\RandomMolecule#1{%
 \multido{\i=1+1}{#1}{%
   \setrandim\Xd{-2pt}{1pt}%
   \setrandim\Yd{-1pt}{1pt}%
   \pscircle*[linecolor=blue](\pointless\Xd,\pointless\Yd){1pt}}%
}
\pagestyle{empty}
\begin{document}

\begin{center}
\psframebox{
\begin{pspicture}(-7,-1.2)(5,1.2)%\psgrid
\psclip{\psframe(-2,-1)(0.8,1)}
  \RandomMolecule{400}%
\endpsclip
\pscircle[doubleline=true,fillcolor=magenta,fillstyle=solid](-6.5,0){0.6}
\psframe[fillstyle=solid,fillcolor=lightgray](-6,-0.5)(-2,0.5)
\psline[doubleline=true,doublesep=2mm](1,0)(3.1,0)
\psframe(-4,1)(0.8,-1)
\psline(0.8,1)(1,0.1)(1,-0.1)(0.8,-1)
\psframe[fillstyle=solid](-4.1,-1.2)(-4,1.2)
\psline[linewidth=2mm](-2,-1)(-2,1)
\multido{\n=-3.5+0.5}{9}{\psline(\n,1)(\n,0.7)}
\rput{-90}(4,0){\manometre}
\end{pspicture}
}
\end{center}

\end{document}
