Two tomographic techniques have been applied simultaneously to the flow of air and silicone oil in 67 mm internal diameter vertical pipe. A twin plane electrical capacitance tomgraphy (ECT) electrode system driven by Tomoflow electronics was positioned below a new capacitance wire mesh sensor (WMS) system. The former used 8 electrodes around the pipe in each plane, the latter employed two arrays of 24 evenly spaced wires stretched over the pipe cross-section. The ECT measurement was triggered from the WMS electronics. High speed videos were also taken simultaneously through the transparent pipe wall. Gas superficial velocities of 0.05-5.5 m/s and liquid superficial velocities of 0-0.7 m/s were studied. These gave bubbly, slug, and churn flow in the pipe. The outputs of the two techniques have been compared at a number of levels. At its most basic, the time averaged cross-sectionally averaged void fractions were compared. They showed excellent agreement. At the next level, the time series of the cross-sectionally averaged void fraction were considered directly and through their variations in amplitude and frequency space. Examples of probability density functions are presented. Radial variations of the void fraction were also considered. Thereafter the shapes of the large bubbles and the velocities of periodic structures are presented.