Vortex flow meters use an obstruction, known as a bluff body, in the flow stream to create downstream vortices which are alternately formed on either side of the bluff body. As these vortices are shed from the bluff body, they create alternating low and high pressure zones that oscillate at particular frequencies directly proportional to the velocity of the fluid. The flow rate can be calculated from the fluid velocity.
Vortex flow meters are universally suitable for measuring liquids, gases and steam while remaining largely unaffected by changes in pressure, temperature and viscosity. Without moving parts, vortex meters are easy to install and require little maintenance. The measuring signal is not subject to drift. Consequently, vortex meters can operate an entire life long without recalibration. Due to the nature of a minimum required velocity for each bluff body, vortex meters will tend to need higher velocities and may have some difficulty reading low flow rates.
Selecting a Flow Meter
The basis of good flow meter selection is a clear understanding of the requirements of the particular application. Therefore, time should be invested in fully evaluating the nature of the process fluid and of the overall installation.
- What is the fluid being measured by the flow meter(s) (air, water, etc…)?
- Do you require rate measurement and/or totalization from the flow meter?
- If the liquid is not water, what viscosity is the liquid?
- Is the fluid clean?
- Do you require a local display on the flow meter or do you need an electronic signal output?
- What is the minimum and maximum flow rate for the flow meter?
- What is the minimum and maximum process pressure?
- What is the minimum and maximum process temperature?
- Is the fluid chemically compatible with the flow meter wetted parts?
- If this is a process application, what is the size of the pipe?
If you have any questions or need any help selecting a flow meter, please contact us at sales@instrumart.com or 1-800-884-4967 to speak with an applications engineer.
