Solids concentration conductivity methods

The application of the Na2SO -Ln2(SO, -SiCLCLj Y and Gd) electrolyte samples as the solid electrolyte for an SC gas detector was investigated. The EMF measurements were conducted by both the SC gas concentration cell(33) and the solid reference electrode(34) methods. Several efforts have been concentrated on the development of the appropriate reference electrode. In our study, the sulfate-oxide solid reference electrode method was adopted. 

In conclusion, the sodium sulfate mixed with rare earth sulfates (Ln=Y and Gd) and silicon dioxide exhibits high electrical conductivity and is more durable than the pure sodium sulfate. Furthermore, the Na-SO, -Y (S0, -SiO solid electrolyte ipaintains a similar phase to Na-oO -I, whicn is excellent in Na+ cation conduction. The measured EMf was in excellent accordance with the calculated EMF, at SO2 gas concentration in the range of 30 ppm to 1 %. In fact, the solid reference electrode method could be applicable as a practical SO2 gas detector. 

Conductivity Probe for Local Solids Concentration Measurements. On the basis of the preceding discussion, local solids concentration can be determined by measuring the mixture conductivity, then using a calibration curve, for example, equation 20. However, using this method to measure solids concentration or dispersed-phase concentration is not an easy task. In the following sections, the development a new conductivity probe will be summarized (24). Also, various problems encountered with conductivity methods will be discussed. 

Calibration. Various methods were used to calibrate the probe. These studies were conducted to find the relation between voltage (e) and solids concentration and to compare the experimental measurements with the predictions of the Maxwell and Bruggeman relationships. It was also necessary to establish an efficient probe calibration procedure. 

Conductivity methods have been successfully used to measure solid concentration in multiphase systems, where the conductivity of continuous phase is greater than zero, for example, sand-water slurries and oil-in-water emulsions (65). These methods have been used to measure bulk and local solids concentration in the slurry pipelines. Nasr-El-Din et al. (27) developed a four-electrode conductivity probe for measuring local solids concentration in slurry pipelines (Figure 20). The probe is... 

Various techniques are available to measure velocity and solids concentration profiles in slurry pipeline. Sample withdrawal using an Li-shaped probe can give a representative sample at isokinetic conditions. Other sample devices will produce significant errors that must be corrected. Conductivity probes can be used to measure local velocity and concentration profiles simultaneously. However, the carrier fluid should be conductive. NMR imaging methods do not disturb the flow with a probe however, they are limited to pipes of small diameter. 

We have already discussed diffusion in solids to some degree. While bulk properties such as heat capacity are not sensitive to defect concentration, many other properties such as conductivity are. Thus, the method of preparation becomes important if one wishes to obtain a conductive or... 

Magnetic susceptibility of paramagnetic particles is used to determine the concentration of ion-radicals but yields no structural information. The method often demands solid samples of ion-radical salts. Many ion-radical salts are unstable in the solid state, and this requirement turns out to be a decisive limit. Fortunately, there are special ways to determine magnetic susceptibility of paramagnetic particles in solutions (Selwood 1958). However, instruments for such measurements are rarely used in chemical laboratories. Besides, special devices should be used to conduct investigations at different temperatures. 

Vinten AJ, Mingelgiin U, Yaron B (1983) The effect of suspended solids in waste water on soil hydraulic conductivity I. Suspended solid labehng method II. Vertical distribution of suspended solids. Soil Sci Soc Am J 47 402 12 Waite DT, Cessna AJ, Grover R, Kerr LA, Snihura AD (2004) Environmental concentrations of agricultural herbicides in Saskatchewan, Canada Bromoxynd, dicamba, diclofop, MCPA, tril-uralin. J Environ Qual 33 1616-1628... 

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