Video: How do you control mass flow in two directions?

How do you control mass flow in TWO directions?

Alicat Scientific introduces the world’s first bidirectional mass flow and pressure controller: the dual-valve MCD. Control mass flow, volumetric flow and pressure in both directions with stand-alone control and 30 on-board gas calibrations over a 200:1 turndown range. Or control pressure or flow into a closed process, and vent the volume with no need for additional bleed valves or continuous outgassing. The MCD is the single most versatile flow controller in the world.