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US 4,066,528 AGranted
Analytical apparatus
AssigneeImperial Chemical Industries PLC
InventorJohn Rickard Mansfield
Life of this patent
Estimating the term…
Abstract
Apparatus for coulometry comprises (a) an instrumentation amplifier acting as a differential to single-ended potential convertor having high input impedence, (b) means for feeding (a) with the potential between the sensor and reference electrodes of a coulometric cell and (c) and differential potential input amplifier fed by (a) and by means for setting the output of (c) to zero, the phase shift of the apparatus being less than 90.degree..
Claims6
Apparatus for carrying out coulometric analysis which comprises:
- a. an instrumentation amplifier which acts as a differential to single ended potential convertor having a high input impedance,
- b. a coulometric cell having a sensor electrode, a reference electrode, and a generator electrode and means for feeding (a) with the potential between the sensor and reference electrodes of said coulometric cell,
- c. a differential potential input amplifier fed by (a) and by means for setting the output current of (c) to zero at a desired potential difference between the sensor and reference electrodes by feeding a suitable offset potential to (c), the whole apparatus excluding the coulometric cell having a phase shift of less than 90.degree. and responding to direct or low frequency electromotive force input signals.
Dependencies are inferred from the claim text.