The main concern of this research is the two phase flow, which consist of air bubbles submersed in water in reactors cores. The understanding of these such flow activities is paramount to finding out about the efficiency of the process and for safety concerns. This knowledge is also important to control and monitor the flow at the spot or online. The employed method is based on the conductivity principle, and it was chosen because of the cheapness of the circuitry involved for implementation, as compared to other imaging techniques. Keeping this in mind, it provides an excellent temporal and spatial resolution for measurement. To fulfill this requirement, a small testing facility was designed and developed. The circuits were made and then tested by making PCBs. To prevent environmental noises and electromagnet disturbance, the apparatus was shielded to the best of ability, in accordance with the available resources. A wire mesh sensor with sixteen inputs and outputs respectively was made and put in a vertical glass section with water and air filled inside. The bubbles were generated by external means and the signal interference was noted in the collection section. The signals were collected by a data acquisition card and further manipulated in a software program. The data was first taken in the LabVIEW software and then transferred to MATLAB for analysis and image reconstruction. Basically, the main system included wire mesh, the circuit for excitation, the circuit for data collection and data acquisition card connected to a computer. The results were compared with a high speed camera which was linked in synchronization with the software. In these circuit designs, the maximum efficiency was ensured while keeping the cost low. The sensor is surrounded by glass so that the high speed camera could also be used to compare results. The use of the high speed data acquisition card also enabled to deal with real time acquisition without any problem. Unfortunately, this facility could not be tested in rigorous conditions like high temperature and pressure because of limited resources. The conclusions drawn from these experiments are that wire mesh sensors indeed provide temporal resolution of about 1000 frames/s with a good spatial resolution and is also a lot cheaper in comparison with other techniques.

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