A test of K(+)-sensitive electrode responses to changes in K+ concentration

Tests of K(+)-sensitive microelectrodes were made using a plastic chamber, which consisted of upper and lower compartments separated by a partition with a small opening in the center. After the upper and lower compartments were filled with 25 and 100 mM KCl respectively, the tip of a K(+)-sensitive electrode was moved up and down through the partition opening, while recording potential changes. Some hydrodynamic events associated with electrode movement and effects of gravity upon spherical diffusion are discussed.