Electrical conductivity of dilute aqueous phosphate solutions and phosphoric acid at elevated temperatures and pressures

Abstract A combined pressure vessel and conductivity cell suitable for use at pressures up to 16 atm. and temperatures up to 200° is described. This equipment has been used to measure electrical conductivities of sodium phosphates and phosphoric acid at low concentrations (phosphates 0.0006–0.01M, H3PO4 0.13M). With each substance, the conductivity attained a maximum and then decreased with increasing temperature. The temperatures where conductivities were maximum were lower than those previously reported for uni‐ and di‐valent salts.