Clear tube flow meter

A clear tube flow meter is an expedient which processes the volumetric flow rate of liquid in a padlocked duct. It is a type of meter known as variable area meters, which calculate the rate of liquid flow by changing the cross-sectional area when the liquid passes through that area, producing a quantifiable consequence.

• A rotameter requires no external power or fuel, it uses only the inherent properties of the fluid, along with gravity, to measure flow rate. 
• A rotameter is also a relatively simple device that can be mass-manufactured out of cheap materials, allowing for its widespread use.
• Since the area of the flow passage increases as the float moves up the tube, the scale is approximately linear.
• Clear glass is used which is highly resistant to thermal shock and chemical action.