Apparatus is disclosed for measuring the electrochemical activity of a liquid, for example, the hydrogen ion activity or pH value of blood. A disposable cartridge includes spaced indicating and reference electrodes which develop electrical properties as a function of the electrochemical activity. The...http://www.google.fr/patents/US4397725?utm_source=gb-gplus-shareBrevet US4397725 - Apparatus for measuring electrochemical activity
