Georgia Tech Research Corporation

Computer Microfilm International Corporation

Gerald E O'Brien

Peter E Sturrock

David L Smith

An instrument and method for measuring chemical properties, the instrument having electrodes suitable for immersion in a chemical solution. A voltage source and a current-sensing circuit are connected to the electrodes to measure the current produced in the solution in response to a voltage applied to the electrodes to determine a value of the chemical in the solution. The instrument and method further include background compensation for offsetting the value of the analyte by an amount which is reflective of the background value of the solution. The background value is stored in an internal memory of the instrument so that when new experimental measurements are taken, the measurements are immediately offset by the background portion of the new experimental measurements. This allows operation of the instrument at high gain levels, resulting in a broad dynamic range and greater useful precision in the output signal.

Digital electrochemical instrument with background compensation

A system for identification and quantification of electrochemically active compounds in a flow stream involves stepping the electrode potential in a detector rapidly through the range of interest with a square wave superimposed on a staircase signal and recording the current response as functions of step number and sweep number, i.e., as functions of voltage and time. From the recorded data, a three-dimensional graph (potential, time and current) is structured and from which identification and quantification of the electrochemically active compounds is effected with minimum expenditure of time. The system includes a potentiostat controlled by a computer with, however, independent logic control contained in the potentiostat. Provision is also made to compensate automatically for variations in resistance between the cell electrodes.

Rapid-sweep electrochemical detector for chemical analysis of flow

A microfilm display device is responsive to a film address signal and controlled by a microprocessor to locate a desired film and select a film image for display on a cathode-ray terminal. The film image is converted to a video signal for display on the terminal. The video signal is used for fine positioning of the raster on a flying spot scanner which illuminates the film.

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Atlanta, GA, United States of America

Gerald E O'Brien