Hi Richard/Heidi, The Fill station works well.  It takes the guess work out of trapped air bubbles in the smaller sample cells.  I use it everyday. Regards, Linda Stephan Production Scientist Quality Control, Milwaukee A business of Merck KGaA, Darmstadt, Germany Sigma-Aldrich Corp. I 6000 N. Teutonia Ave. I  Milwaukee, WI 53209 / USA