Nonconducting media

Fig. 8. Capacitance-based level measurement, nonconductive media.

In nonmetaUic vessels, the second plate of the capacitor is missing and must be suppHed. A stiUweU probe, one with a concentric metal tube, is utilized. The concentric tube suppHes the second plate. StiUweU probes have numerous other uses. In appHcations of nonconductive media, a stiUweU probe is more sensitive and suppHes a greater amount of capacitance because the ground reference is so close to the probe. Further, if a tank waU offers a ground reference that is a varyiag distance to the probe, eg, a horizontal cylinder, the stiUweU offers a much more consistent (linear) ground reference. 

One difference between conducting and nonconducting media is that in the former case a charge balance may take the place of one of the material balances. For the same number of solution species, however, the number of independent balance equations is the same in the two cases. 

The electrical resistance (ER) technique is an online method of monitoring corrosion rates. It is universally applicable to aU types of corrosive environments, i.e., conductive to poorly or nonconductive media (such as deionized or potable waters) and vapor phase systems (such as steam). 

Toniolo R, Comisso N, Bontranpelli G, Schiavon G, Sitran S (1998) A novel assembly for perfluorinated ion-exchange membrane-based sensors designed for electroanalytical measurements in nonconducting media. Electroanalysis 10 942... 

Bontempelli G, Comisso N, Toniolo R, Schiavon G (1997) Electroanalytical sensors for nonconducting media based on electrodes supported on perfluoiinated ion-exchange membranes. Electroanalysis 9 433-443 Cao Z, Stetter JR (1991) Amperometiic gas sensors. In Madou M, Joseph JP (eds) Opportunities for innovation chemical and biological sensors. NIST Publication GCR 91-593-1, U.S. Department of Commerce, Gaithersburg, MD Cao Z, Buttner WJ, Stetter JR (1992) The properties and applications of amperometric gas sensors. Electroanalysis 4 253-266... 

Introducing the absolute value of Equation [7] into Equation [6] results in, for nonconducting media. 

Bontempelli G, Comisso N, Toniolo R, Schiavon G (1997) Electroantilytical sensors for nonconducting media based on electrodes supported on perfluorinated ion-exchange membranes. Electroanalysis 9(6) 433 43... 

However, a few neutral polymers have demonstrated high actuating deformation under electric filed in nonconducting media such as silicone and poly(dimethylsiloxane)— PDMS with titanium dioxide particles (Fig. 3.2) (Filipcsei et al., 2000). Moreover, piezoelectric polymers, such as the poly(vinylidene fluoride)—PVDF and its copolymers, feature interesting properties for sensors and actuators applications such as artificial... 

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