\begin{table}%t1
\caption{\label{tbl-1}Various discharge conditions: $C$-bank capacity (in
$\mu$F), $U$-bank voltage (in~kV), $H$-plasma length (in~cm),
$\Phi$-tube diameter (in~mm), $P$-filling pressure (in Pa).
$N^{\rm exp}$ (in~10$^{\rm 22}$~m$^{\rm -3}$) and~$T^{\rm exp}$ (in~10$^{\rm 3}$~K) denote experimental electron density and
temperature, respectively obtained at a moment when the line
profiles were analyzed. $N^{\rm D}$ (in 10$^{\rm 22}$~m$^{\rm -3}$)
and~$T^{\rm D}$ (in 10$^{\rm 3}$~K) represent averaged electron
density and averaged electron temperature obtained by using our
line deconvolution procedure \citep{Mil01a}.}
%\centering
\par
\begin{tabular}{ccccccccccc}
\hline
\hline 
\noalign{\smallskip}
Working gases & Exp. & $C$ & $U$ & $H$ & $\Phi$ & $P$ & $N^{\rm exp}$ & $N^{\rm D}$ & $T^{\rm exp}$ & $T^{\rm D}$ \\
\noalign{\smallskip}\hline \noalign{\smallskip}
72\% Ar + 28\% He  & a & 14 & 1.5 & 7.2 & 5 & 133 & $6.7~\pm$~7\% &$6.9~\pm$~12\% & $15.6~\pm$~11\% & $15.8~\pm$~12\% \\
97\% Ar + 3\% H$_2$ & b & 14 & 1.5 & 7.2 & 5 & 67 & $7.0~\pm$~7\% &$7.3~\pm$~12\% & $16.0~\pm$~11\% & $16.2~\pm$~12\% \\
97\% Ar + 3\% H$_2$ & c & 14 & 1.5 & 7.2 & 5 & 133 &$7.1~\pm$~7\% &$7.4~\pm$~12\% & $16.2~\pm$~11\% & $16.5~\pm$~12\% \\
 \hline
\end{tabular}
\end{table}