Radiometer A/s

Torben F Christiansen

Finn Kokholm

A reference liquid for calibration or quality control of instruments which determine ionized calcium and pH. The reference liquid contains both a particular calcium ion activity and a pH-buffer and can therefore be used for calibration of both the calcium-sensitive electrode and the pH-electrode in the instruments. The pH-buffer is a nitrogen-containing organic sulphonic acid and the salt of this acid, the acid having a pK in the range of 6.6-7.6. The reference liquid has an ionic strength of 0.15-0.17, a buffer capacity .beta. in the range of 0.04-0.10 and is packed in glass ampoules.

Reference liquid

An electrochemical measuring electrode device (10) for polarographically measuring the partial pressure of oxygen in an electrolytic medium comprises a cathode (14) which is capable of reducing oxygen and defines an exposed oxygen-reducing cathode surface (20), an anode (18), which defines an exposed anode surface which is arranged relative to the exposed oxygen-reducing cathode surface so as to communicate electrolytically therewith through the electrolytic medium, and a membrane (24), which covers the exposed oxygen-reducing cathode surface and further defines an electrolyte chamber (22) in which the electrolytic medium is confined. In order to effectively promote the decomposition of H.sub.2 O.sub.2 generated in the electrolytic medium as an oxygen reduction intermediate and thereby reduce the response time of the electrode, a stable, non-biological catalytic means is provided catalytically communicating with the H.sub.2 O.sub.2. The stable, non-biological catalytic means is preferably constituted by platinum black particles which may be received by the membrane at a central region (42) thereof or alternatively be received by a support structure which may further constitute a covering of at least part of the membrane ( 24).

Membrane for an electrochemical measuring electrode device

An electrochemical measuring electrode device (10) for polarographically measuring the partial pressure of oxygen in an electrolytic medium comprises a cathode (14) which is capable of reducing oxygen and defines an exposed oxygen-reducing cathode surface (20), an anode (18), which defines an exposed anode surface which is arranged relative to the exposed oxygen-reducing cathode surface so as to communicate electrolytically therewith through the electrolytic medium, and a membrane (24), which covers the exposed oxygen-reducing cathode surface and further defines an electrolyte chamber (22) in which the electrolytic medium is confined. In order to effectively promote the decomposition of H.sub.2 O.sub.2 generated in the electrolytic medium as an oxygen reduction intermediate and thereby reduce the response time of the electrode, a stable, non-biological catalytic means is provided catalytically communicating with the H.sub.2O 2. The stable, non-biological catalytic means is preferably constituted by platinum black particles which may be received by the membrane at a central region (42) thereof or alternatively be received by a support structure which may further constitute a covering of at least part of the membrane (24). The platinum black particles may be pressed into a foil material constituting a base material of the membrane or alternatively be applied in a suspension to the membrane whereupon the suspension is solidified.

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Holte, Denmark

Torben F Christiansen