PROCESS AND APPARATUS FOR MEASURING THE CONCENTRATION OF A COMPONENT OF A LIQUID

摘要

1286298 Electro-chemical analysis SIEMENS A G 4 Dec 1969 [5 Dec 1968] 59372/69 Heading G1N [Also in Division H1] The concentration of e.g. hydrazine in an electrolyte is monitored by an electro-chemical cell with one electrode (e.g. a platinized nickel grid) behind a porous membrane (e.g. of asbestos fibre paper) and a bias of about 1 volt applied so that it operates in the diffusion limiting range. Modifications:-The membrane may be formed with coarse pores at the margins away from the electrode; an ion-exchanger resin membrane may be used; the cell may be formed as a ceramic "testtube", Fig.3 (not shown). Control. The cell may be used to control the hydrazine pump of a fuel-cell system in accordance with the deviation of hydrazine concentration from a reference valve derived from the cell load current in conventional manner, Fig.4 (not shown).