Flow Measurement

A rotameter is a flow measurement device used for measuring the flow rate of a fluid (liquid or gas) passing through an enlarged vertical pipe (typically a cone-shaped tube). It operates on the variable area principle, where the position of a float within the tube directly indicates the flow rate.
• Simple, robust, and cost-effective.
• Do not require electrical power (in their mechanical version).
• Ideal for low flow rates and fixed installations

Laminar mass flow meters calculate mass flow by measuring the pressure drop across laminar flow elements.
Operating Principle
These flow meters are equipped with a laminar restriction element through which the fluid flows in a laminar regime. When the gas passes through this element:
• a pressure drop occurs between the inlet and outlet of the laminar element,
• this pressure drop is proportional to the volumetric flow rate in the laminar regime,
• knowing the temperature and pressure of the gas, the mass flow rate can be calculated accurately.
Advantages
• Very good accuracy even at low flow rates,
• Fast and linear response in the laminar regime,
• Low sensitivity to gas composition (if properly calibrated).

Thermal mass flow meters utilize the thermal properties of gases to directly measure the mass flow rate of a gaseous fluid.
• Direct measurement of mass flow (no need to correct for temperature or pressure).
• Ideal for pure gases.
• Very few moving parts → reduced maintenance.