Adaptation of a Sargent polarograph to a pen recording instrument

Adaptation of a Sargent Polarograph to a Pen Recording Instrument J. W. Haas, Jr. Gordon College, Wenham, Massachusetts

The Sargent Model XI1 Polarogwphl is widely available in educational laboratories. Current-voltage curves are plotted manually or recorded by photographic means. The Sargent instrument is easily converted to a pen-writing instrument by connecting the galvauon~eterleads to a 1-or 2.5-mv potentiometrie recorder (remove the galvanometer from the circuit). Recorder input results from the potential drop across the shunt of the polarograph and is a function of current and shunt resistance. Recorder calibration follows the procedure normally used for calibration of the galvanometer. The oscillations in the polarographic wave due to periodic growth and fall of the mercury drops may be effectively damped by connecting two 1000 p farad electrolytic 6-v capacitors in series with opposed polarity2 across the recorder input. ' H. E. Sargent & Co., 4647 West Foster Ave., Chicago 30, Ill.

KOLTHOFF, I. M., AND LINQANE,J. J., "PoIarogmphy," 2nd ed., Int,erscieneePublishers, New York, 1952, Vol. 1, p. 325.

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Journal of Chemkol Education