What does a mass flow controller do?
A mass flow controller automatically controls the flow rate of a gas according to a set flow rate sent as an electric signal, without being affected by use conditions or changes in gas pressure. Flow rates can be roughly classified into two types: volumetric flow and mass flow.
Where are mass flow controllers used?
Mass flow controllers are used in the semiconductor industry to measure and control many of the gases used in the semiconductor chip-making process. This includes chemical vapor deposition (CVD), plasma etching processes, backside water cooling, and many other applications in semiconductor manufacturing.
What is the difference between mass flow meter and mass flow controller?
A meter measures flow and gives an output signal proportional to flow. A controller will also have a valve on board and can manipulate the flow by throttling a valve.
In what devices flow controllers are useful?
Flow controllers are used primarily in process control applications. They are made for gases as well as liquids of many types, and are available in many sizes and configurations depending on the application.
What is the difference between volumetric flow meter and mass flow meter?
Volumetric flow meters are recommended when measuring volumetric flow of the gas and when high accuracy is not needed. However, when comparing results, a volume flow meter requires additional temperature and pressure compensation. Whereas mass flow meters measure flow rate independent of gas pressure and temperature.
What is difference between mass flow and volumetric flow?
As it is commonly known, Mass flow measures the number of molecules in a flowing gas, whereas volumetric flow measures the space that those molecules occupy. As gases are compressible and widely affected by temperature, volumetric flow rates can significantly change depending on pressure and/or temperature changes.
What is a gas flow controller?
A gas mass flow controller is an instrument used to measure and control the flow of gases. These controllers are built, tested, and calibrated for specific operating conditions (flow range, type of gas, upstream pressure, downstream pressure, and temperature).
What is LPM and SLPM?
The standard liter per minute (SLM or SLPM) is a unit of volumetric flow rate of a gas at standard conditions for temperature and pressure (STP), which is most commonly practiced in the United States, whereas European practice revolves around the normal litre per minute (NLPM).
When would you use a mass flow meter?
They provide high accuracy in mass flow measurement, density measurement, temperature measurement, and viscosity. Thermal mass flow meters are often used in monitoring or controlling mass-related processes such as chemical reactions that depend on the relative masses of unreacted ingredients.
How do you read a gas flow meter?
The gas flow rate is read from the position of the top of the bobbin of the flow meter. In flow meters with a ball, rather than a bobbin (right), the reading is taken from the centre of the ball.
What are the applications of controllers?
Proportional-Integral-Derivative (PID) controllers are used in most automatic process control applications in industry today to regulate flow, temperature, pressure, level, and many other industrial process variables.