Abstract Colloidal gas aphron (CGA) characterization demands further investigation for exploring its potential ability in separation processes. In this paper, both integrated and differentiated electrical conductivity (EC) of CGA dispersion was measured and compared with surfactant concentration. They confirm each other well. The range of concentration of anionic surfactant for producing CGA was chosen from below the critical micelle concentration (CMC) up to above it. EC technique results in differentiating three separate stages compared with two stages in conventional aphron drainage method. The experimental results show that EC data is a good indicator for probing and characterizing the CGA dispersion. The most interesting aspect of EC results is that EC data (an intensive property) follows fairly well the cumulative drainage volume (an extensive property).