Patent ID: 6551480
Filing Date: 2003-04-22
Classification: G01N

Abstract:
A reference electrode for contacting an ion-containing sample comprising an electrode plug and a chamber (16) closed at the rear and containing an ion-containing electrolyte, the chamber (16) having an aperture (23) covered by a membrane (26) of a material permitting diffusion of ions therethrough, but whose surface is closed for proteins and similar macromolecular substances, the reference electrode further comprising a diffusion tight diaphragm membrane (27) being situated on the outer side of the ion diffusion membrane (26) relative to the chamber (16), the diffusion tight diaphragm membrane (27) having a through-going orifice (30) which is located within the aperture (23) and is smaller than the aperture (23), whereby diffusion of ions from the electrolyte to the ion diffusion membrane is greater than diffusion of ions from the sample to the ion diffusion membrane.