Wire electrode resistive sensor for liquid metal surface level measurement

A wire resistive sensor has been implemented and successfully tested to measure the thickness of liquid metal film for fusion applications. This sensor (made by Taha) is an improved version of the previously implemented resistive sensor, in which the plate electrodes have been replaced by wire electrodes. Wire electrodes benefit finer local surface level measurement of liquid metal, compared to plate electrodes.

The sensor is based on a simple measurement of the electrical resistance of the liquid metal. A matrix of electrodes in different heights are embedded in a plastic pot which contains the liquid metal (Fig. 1). Results (Fig. 2) show a good agreement between the liquid metal depth measured by the wire resistive sensor (long wires) and a simple Teflon coated ruler and also the expected resistance behavior for different liquid metal thicknesses. The best measurements have been accomplished using the longest electrodes.

Fig. 1: Wire resistive sensor to measure the liquid metal film thickness using the measured resistance between the electrodes.

 

   
Fig. 2: Wire sensor measurements vs. ruler sensor measurements (left) and measured resistance for different liquid metal thicknesses (right)
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