IL40148A

IL40148A - Self-compensating electrode system for measuring ph

Info

Publication number: IL40148A
Application number: IL40148A
Authority: IL
Original assignee: Great Lakes Instruments Inc
Priority date: 1972-08-17
Filing date: 1972-08-17
Publication date: 1976-04-30
Also published as: IL40148A0

Claims

Appln.No. 40148/2 C L A I M S

1. A device for measuring ion concentration or electrode potential in an electrolytic test solution comprising: a first measuring electrode means including a first sensing element and an electrolytic standard solution in contact therewith and containing ions corresponding with those to be measured in said test solution, said electrode means producing a first potential in response to said standard solution and said means being constructed and arranged for said standard solution to be placed in electrolytic contact with said test solution, a second measuring electrode means including a second sensing element composed in the same material as the first sensing element, said second electrode means being constructed and arranged for being placed in said test solutii for said second sensing element to produce a second potential in response to ions to be measured in said test solution, a reference electrode means constructed and arranged for being in electrically conductive relationship with said test solution to be measured simultaneously with said first and second electrode means, said reference electroi means serving as a common electrical reference point for said first and second electrode means, said reference electrode means being connected to the common potential reference point of the measuring circuit, means for measuring the potential difference between said first electrode means and said reference electrode means, < means for measuring the potential difference between said second electrode means and said reference electrode means, and means for measuring the differential potential between said measured potential difference,

2. The device claimed in claim 1 wherein each of said means for measuring the potential difference between said first electrode and said reference electrode and between said second electrode and said reference electrode comprises a non-inverting high input impedance amplifier means, each of said amplifier means having an output terminal, and non-inverting and inverting input terminals, the non-inverting terminal of one amplifier means being connected to the sensing element of said first electrode means and the non-inverting terminal of the other amplifier means being connected to the sensing element of said second electrode means, the inverting terminal of each amplifier means being connected to its output terminal respectively, each said amplifier means being for producing said potential on its output terminal corresponding to the potential it measures between its non-inverting terminal and said reference electrode, said means which measure the differential potential between said measured potential differences being connected between said amplifier means output terminals.

3. The device as claimed in claim 1 and including a buffering solution between said standard solution and said test solution of unknown ion concentration*

4. The device as defined in Claim 2 wherein said electrodes are of the standard glass pH type. Αρρΐη» 40148/2

5. The device as defined in Claim 2 wherein both said electrodes are of the dissolved oxygen detecting t pe.

6. The device as defined in Claim 6 wherein said sealed container is further enclosed in a second similar container filled with a solution to remove oxygen,

7. The device as defined in Claim 1 wherein said electrodes are placed a substantial distance from each other.