Marc Ruppenthal wrote:

> I am not searching for advice how to best tune up measurement results. :-)

That was not what I've tried to tell (but my reply can be interpreted 
like this, I admit). It was more a general warning of using some 
statistical calculations without using common sense.

Using advanced statistical methods for error calculation, data fitting 
etc. is an issue which deserves definitely more attention in geoscience. 
However, the first step is to understand what a statistical parameter 
tells you [which is not as easy as it looks at the first glance] and 
then decide which method, parameter or calculation should be used.

regards,
Robert