Electrode sample handling system

The outline of the construction of a plasma emission spectrometer may be inferred from figure 8.3 with a plasma source replacing the electrode system. Instruments are computerized and make use of automatic sample handling. 

The advanced IC fabrication techniques have opened up a new window to fabricate nhniaturized devices, and are called micromachining It has permitted the fabrication of miniaturized gas chromatographic systems for the use in space laboratories Subsequent efforts have extended the technique to the field of chemical measurement, allowing plate-type sensors, such as ISFET and thin-layer electrodes, which handle a sample outside of the device, to be produced by photolithographic techniques... 

Square wave voltammetry is always performed using a computer-controlled potentio-static system with functional elements organized essentially as in Figure 7.3.11. The computer provides for operator interaction, synthesizes the waveform, sequences the sampling and logging of data, computes difference currents, and handles reporting of results, either graphically or otherwise. In many systems, the computer also controls the electrode, especially if an SMDE is involved. 

Some manufacturers, such as AMEL Instruments, have started to commercialize Zirconia pH electrodes for temperatures higher than 160 C. These electrodes could potentially handle much faster disturbances, but the long-term drift in actual process applications needs further investigation. Even though the speed of response may degrade with time, the large transportation delay associated with sample systems has been eliminated. 

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