Capacitance sensor for void fraction measurement in water/steam flows

Liquid holdup measurement with double helix capacitance sensor in horizontal oil–water two-phase flow pipes

“…In general, the proposed double helix capacitance sensor has low sensitivity when the conductive water phase is the only one in contact with the flow pipe. To address this issue, Jaworek et al [36] have used an 80 MHz oscillator to overcome the conductive effect of water, but the high working frequency entails problem related to the measurement circuit. It has been shown that large axial length of electrode [35] and large range edge guarding electrode [24] can greatly reduce the current losses.…”

Characterization of gas-liquid two phase flows using dielectric Sensors

“…4. To benchmark experimental results the value of time of trough is measured from Multisim simulation in which the dielectric constant in case of single phase air, water and oil (respective dielectric constants are 1.0001, 80 and 4.5) is given as input based on Bruggeman′s theory of parallel capacitance [14]. The time of trough value obtained for air, water and oil in simulations are presented in Fig.…”

“…Ahmed and Ismail [13] used a capacitance meter with 1 MHz excitation frequency to determine the volume of air in airoil two phase flow. Jaworek et al [14] used a RF oscillator to distinguish steam from water. Unlike previous methods which were based on direct measurement of capacitance values, Jaworek and Krupa [15] used a Phase Shift measurement technique to determine accurately the void fraction.…”

Differential C4D sensor for conductive and non-conductive fluidic channel

“…Jaworek et al presents a high frequency capacitance sensor to solve the conductive effects of water using an 80 MHz oscillator. However, that device requires an extremely short electrodes for a quasi-local measurement and a rather complicated circuit (Jaworek et al 2004).…”