A permanent Cu/CuSO4 half cell with ceramic membrane was metrologically studied relative to its
potential and durability. In this evaluation the half-cell potential only reaches stable values after 480
hours, reaching a value between thermodynamic value and that of an aged electrode. However the
thermal coefficients, entropy of half-cell reaction, continued to change, reflecting variable gel
participation in cell reaction. Field variables such as presence of chlorides, sugarcane fermented
waste, containing acetates and ammonium salts, and as well as CuSO4 leaching were studied. The
chloride resistance of the electrode was 50 hours for a sea level chloride content, accompanied by
change in electrode appearance. The sugar cane fermented waste did not affect the electrode
behavior even after exposure to pure waste for 2400 hours. CuSO4 leaching was only 0.9 g/l after 3000
hours immersed in distilled water accompanied by no change in potential. This is acceptable since
electrode CuSO4 content is over 40 grams.