Electrical transport properties can be measured at high PT in the Paris-Edinburgh cell (PEC) through a four-wire probe method. The top portion of Fig. 1 illustrates the general working principle. Two pairs of thermocouples are brought into the PEC and placed in contact with the top and bottom faces of the sample. The setup allows for two measurement modes. In the first mode, a constant DC current is passed through the sample and the voltage is measured. Changes in the sample resistance can thus be linked to phase changes in the material (see bottom left plot of Fig. 1) or the sample dimensions can be recorded with radiography (bottom right plot of Fig. 1) and combined with the resistance data to calculate the material resistivity. In mode 2, application of DC current is paused and the thermocouples are used to measure the sample temperature. Software to collect and analyze the transport data is available at HPCAT.