Alternative system to measure hydrogen content in molten aluminium using an electrochemical sensor

The most reliable techniques for the direct measurement of hydrogen content in liquid aluminium are based on Sievert’s law or use electrochemical probes introduced directly in liquid aluminium. The main drawback of these methods is the high cost of the equipment. An alternative apparatus has been developed and tested. This equipment combines a widely used and much cheaper hydrogen electrochemical sensor with the procedure already patented and commonly used by gas recirculation techniques. The device has been constructed and calibrated using gaseous mixtures of known hydrogen content. For validation, the results obtained with this apparatus have been compared with hydrogen content measurements in liquid aluminium using the commercial Alscan equipment in an industrial facility. Experimental results suggest that the apparatus proposed in this work is capable of detecting hydrogen content in liquid aluminium obtaining measurements that are in a good agreement with those obtained using the commercial Alscan equipment. On the other hand, results also suggest that it is important to take into account the operating atmospheric pressure to correct the readings obtained from Alscan when operating at atmospheric pressure levels far from 1 atm.