A Polarograph is a chemical analysis instrument used to record automatic voltage-intensity curves. The Polarograph uses an electrolytic cell consisting of an electrode or

microelectrode A microelectrode is an electrode used in electrophysiology either for recording neural signals or for the electrical stimulation of nervous tissue (they were first developed by Ida Hyde in 1921). Pulled glass pipettes with tip diameters of 0. ...

small area, generally of mercury drop type, which is a very fine

capillary tube Capillary action (sometimes called capillarity, capillary motion, capillary rise, capillary effect, or wicking) is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces li ...

through which mercury flows slowly, which comes in the form of small droplets, which fall on the same surface of a much broader element, which is the other electrode . When one applies a variable voltage in this cell, the electrode large area remains unchanged, while the

undergoes a change of potential, ( i.e. is polarized). It also has a

potentiometer A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat. The measuring instrume ...

coupled to the motor that moves the recording paper so that a certain voltage variation corresponds to a constant length of recording paper, and a galvanometer suitable for measuring the intensity of the electric current, whose response is transmitted to the actuator that moves the needle of the recorder. The technique used is called

polarography Polarography is a type of voltammetry where the working electrode is a dropping mercury electrode (DME) or a static mercury drop electrode (SMDE), which are useful for their wide cathodic ranges and renewable surfaces. It was invented in 1922 by C ...

.
polarògraf
�. It was invented by the Czech chemist and Nobel Prize winner

Jaroslav Heyrovský Jaroslav Heyrovský () (December 20, 1890 – March 27, 1967) was a Czech chemist and inventor. Heyrovský was the inventor of the polarographic method, father of the electroanalytical method, and recipient of the Nobel Prize in 1959 for his ...

References

Laboratory equipment