Microelectrodes electronic equipment

When posing the question why use a microelectrode, some of the first answers that might come to mind are that one has only a very small volume of material to study or that one wishes to position the electrode in a very small place. The most obvious example of this type of application is in in vivo studies and these will be discussed briefly in the next section. The remainder of the chapter is concerned with a discussion of the various properties of microelectrodes, such as reduced iRu drop, that arise as a result of their small dimensions, and the way that these properties can be utilized to good effect. The various methods that have been used for the fabrication of microelectrodes and the electronic equipment required for these studies will also be described. 

For most voltammetric and amperometric methods, the instrumentation includes a working microelectrode, a reference electrode and an auxiliary or counter electrode, together with electronic equipment to control the voltage and voltage sweep, plus a computer or recorder to collect data. 

Fig. 3.21 Schematic representation of the mechanic and electronic unit applied to microelectrodes in a lander system. The round pressure cylinder contains the electronic control equipment and the data monitoring device, to the bottom of which various vertically positioned microelectrodes are mounted. The entire cylinder is lowered with the aid of a stepper motor and a corresponding mechanical system in pre-adjustable intervals so that the electrodes begin measuring in the bottom water zone and then become immersed into the sediment (after Reimers 1978).

---