\documentclass[border=10pt]{standalone}
%%%<
\usepackage{verbatim}
\usepackage{filecontents}
\begin{filecontents}{data.csv}
measuring   power1   result1   power2   result2
1           2        0.2       2.5      0.3
2           3        0.35      3.8      0.3
3           4        0.45      7.9      0.35
4           5        0.5       8.5      0.39
5           6        0.65      8.0      0.38
6           7        0.68      8.0      0.4
7           8        0.7       8.0      0.41
8           7.5      0.73      {}       {}
9           6.7      0.75      {}       {}
10          10       0.79      {}       {}
\end{filecontents}
%%%>
\usepackage{pgfplots}
\pgfplotsset{width=7cm, compat=1.8, grid style={dashed}}
\begin{comment}
:Title: Markers in a line diagram
:Tags: 2D;Markers
:Author: Elke Schubert
:Slug: plot-markers

Besides x and y values, special markers illustrate the result.

This topic was discussed on: http://texwelt.de/wissen/fragen/3363/
\end{comment}
\begin{document}
\begin{tikzpicture}
  \begin{axis}[
    scatter,
    scatter src = explicite,
    grid        = major, % draws coordinate grid
    xlabel      = Force $\lbrack{}$ F $\rbrack$, 
    ylabel      = Amperage $\lbrack{}$ kA $\rbrack$,
    width       = \linewidth,
    height      = 10cm,
    xmin = 0, xmax = 15,
    ymin = 0, ymax = 12,
    ]
    \addplot+ [
      visualization depends on =
        {10*\thisrow{result1} \as \perpointmarksize},
      scatter/@pre marker code/.append style =
        {/tikz/mark size = \perpointmarksize},
    ]
    table[x=measuring, y=power1, point meta=\thisrow{result1}] {data.csv};
    \addplot+ [
      visualization depends on =
        {10*\thisrow{result2} \as \perpointmarksize},
      scatter/@pre marker code/.append style =
        {/tikz/mark size = \perpointmarksize}
    ]
    table [x=measuring, y=power2, point meta=\thisrow{result2}] {data.csv};
    \fill [gray, fill opacity=0.25] (axis cs:5,0) rectangle (axis cs:7,12);
  \end{axis}
\end{tikzpicture}
\end{document}