| abstract |
An ion sensitive electrode structure employing concentrically arranged inner and outer tubular members employs a porous plug to seal the annular space between the tubular members and to enable formation of a salt bridge. The plug is made of porous Teflon and, in preferred form, it is combined with an encompassing sealing annulus which seals an annular space between the outer wall of the plug and the inner wall of the outer tubular member. In a form preferred for some applications, two such plugs and sealing annulus' are employed and are held separated by a spacer. |