Electrochemical timer

The electrochemical timer is a device that can be set to switch a circuit on or off at a given time. It was of great practical importance until the development of microelectronic digital devices, since it could be set to operate for periods of minutes to months, with an accuracy of better than 1%. We describe it here to show how an understanding of the fundamental electrochemical processes taking place can lead to the development of a simple and very useful device. 

To understand the operation of the "electrochemical timer" we must review the current-potential relationship shown in Fig. fA. What happens when there is more than one electroactive species in solution This modification is shown in Fig. 5A for a solution containing Tl and Cd ions, employing a mercury cathode. 

The main timer types are precision reference, electronic, mechanical, pyrotechnic, flueric and electrochemical. Also covered are fluid timers (not to be confused with flueric timers) and nuclear decay timers. Electronic and flueric timers are similar in that they both use oscillators, amplifiers, and related networks to achieve tuning and frequency control. In mechanical... 

Fig. 6. Diagrammatic (A) and photographic (B) representation of biosensor/instrumen-tation required for electrochemical E2 assay. (1) card bearing working electrode and reagent well, (2) Ag/AgCI counter/reference electrode, (3) substrate solution in well, (4) gold connectors, (5) potentiostat, (6) computer, (7) block to support working electrode, (8) substrate stock solution, (9) micropipettor, (10) timer.

Fig. 54. Block diagram of the timer-sequencer-controller for coupling the electrochemical experiment to the interferometer data collect.

Particle Counting and Identification Electrochemical Methods Ion-Specific Electrodes Radioactive Methods Coagulation Timers Osmometers Automation Trends in Laboratory Instrumentation Defining Terms References... 

Devise an experiment to measure a reaction rate using an electrochemical cell, a potentiometer, and a precision timer. (Can reaction kinetics be studied for a reaction in a cell )... 

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