In the present paper, the flow was examined experimentally using air and water as the working fluids. Various sets of experimental data were conducted by varying the superficial velocities within ranges of 0.7-3.84 m/s and 0.7-1.33 m/s for air and water, respectively. The slug characteristics were acquired and computed using non-intrusive optical based technique. Statistical analysis for the translational slug velocity and slug body length was conducted. It was observed that for fixed water velocity, the slug length was increasing with increasing the superficial air velocity while the slug frequency decreased. However, for fixed superficial air velocity, the slug length was decreasing with increasing the water velocity whiles the slug frequency increased. Also, it was found that when the superficial water velocity increased the slugs were formed and initiated far downstream from the pipe inlet section. Furthermore, the obtained results were found in a good agreement with the previous empirical correlation. (C) 2016 Elsevier Ltd. All rights reserved.