I added tags to this post to increase visibility.
Is this post ( In OpenLAB CDS 2.2 - How do you increase the decimal places for your sample weight in the sequence table? ) that you submitted yesterday a duplicate of this question?
As far as I know, there is no way to change the number of decimal places displayed for the Sample Amount column in your sequence table. You can, however, change how many decimal places are shown for your sample amount on your injection reports by editing the report properties.