Solids concentration conductivity probe methods

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. 

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