87. 7 Thermodynamics of reversible cell 7.7.1. Measurement of Electromotive forces(emfs OPle Vout Counter ectrode Reference Voltage Electrode 运算放大器: Operational Amplifier7.7.1. Measurement of Electromotive forces (emf's) §7.7 Thermodynamics of reversible cell 运算放大器： Operational Amplifier