Polarograph

Workstation with a polarograph on the left

A polarograph is a chemical analysis instrument that is used for automatic recording of current-voltage curves.

The polarograph uses an electrolytic cell consisting of a small electrode or microelectrode, usually a mercury drop, consisting of a very thin capillary tube through which mercury flows slowly, which is released in the form of small droplets, which fall on a surface of the same much more extensive element, that constitutes the other electrode. When a variable voltage is applied to this cell, the large surface electrode remains unchanged, while the microelectrode undergoes a potential change, that is, it is polarized. It also has a potentiometer coupled to the motor that moves the recording paper so that at a given voltage variation a constant length of the recording paper corresponds and a galvanometer suitable for measuring the current of the electric current, the response is transmitted to servomotor that moves the needle of the recorder. The technique used is called Polarography.

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