\begin{table}%t2
\caption{\label{Tab:quality}Data quality: the table lists the ranges of the rms values of
  the phase and amplitude between all baselines for each observing epoch
  and wavelength. Also, the estimated systematic error of the absolute
  flux calibration is indicated.}
\small      
%\centering
\par
\begin{tabular}{lcccccc}
\hline\hline       
     & 3~mm & 3~mm & 3~mm & 1~mm & 1~mm & 1~mm \\
Date & phase rms [deg] & amp rms [\%] & absolute & phase rms [deg] &
     amp rms [\%] & absolute \\
\hline                    
24-Feb.-2005    & 10--20 & 5--8     & $\leq$10\% & 20--40 & 11--18 &
     $\leq$15\% \\
14/15-Jul.-2005 & 15--35 & 8--11    & $\leq$15\% & 40--60 & 25--30 &
     $\leq$30\% \\
19/20-Jul.-2005    & 12--28 & $\sim$3 & $\leq$15\% & 30--70 & 11--18 &
     $\leq$20\% \\
\hline                  
\end{tabular}
\end{table}