A flow meter quantifies the movement of a fluid including gas, liquid and steam through closed conduits. Flow can be measured by several types of technology. Mechanical flow meters are positive displacement meters such as turbine meters and variable area meters. These flow meters fill with a fixed volume of fluid and then are divided by the time gives the flow rate. Other flow meters are based on measuring the differential pressure like Venturi or orifice plates. Differential pressure devices traditionally have fast response, but measure volumetric flow and must calculate mass flow.
However, thermal mass flow technology is an industry standard for mass flow control of gases because it measures flow directly at the molecular level. In essence, counting and controlling every gas molecule flowing through the instrument to achieve unmatched precision. The molecular mass or weight of the flowing gas is what you really care about when optimizing your flow process. Because thermal mass flow controllers measure gas mass flow rate directly, they remain unaffected by temperature or pressure effects. It doesn’t matter how hot or cold the gas is or what pressure fluctuations may be happening upstream. You always get smooth, steady, accurate and extremely reliable gas mass flow rate delivered where you need it, every time.
Find out more in this in-depth white paper from Sierra CEO & Founder Dr. John G. Olin.