Selecting a Flow Meter
A flow meter is used to measure linear, nonlinear, mass or volumetric flow rate of a liquid or gas. In order to properly select a flow meter, one must evaluate the particular application. Here are some key questions when making a selection:
What is being measured, gas or liquid? What type?
What is the viscosity of the liquid?
Is the fluid clean?
Is continuous or totalized flow rate information required?
Is the information needed locally or remotely?
Analog, digital, or shared transmission?
Minimum and maximum flow rates for the flow meter?
Minimum and maximum process pressures?
Minimum and maximum process temperatures?
Is the fluid chemically compatible with the flow meter wetted parts?
Is this a process application? If so, what is the size of the pipe?
Where will the flow meter be located? Careful consideration must be given to size of upstream and downstream piping/ductwork to prevent turbulent, erratic, low- or non-flow.
Other considerations should include the level of ability of plant personnel, their experience with calibration and maintenance, spare parts availability, etc., all of which factor in to calculating overall costs. Make sure the flow meter you choose has been factory-calibrated.
Finally, as with any instrument, select a flow meter that will provide optimal performance for your application, rather than choosing based on initial cost and trying to make it fit your needs. The latter usually ends up costing far more in the long run.
Omni Instrumentation & Electrical Services, Inc., located in New Jersey and Maryland, is a premier instrumentation and electrical contractor, providing superior total care solutions since 1986. Services include instrument installation, tubing installation, instrument calibration, control loop testing, startup and commissioning, power and lighting, process control wiring, BMS wiring, telecommunications and data wiring, fire alarm wiring, security wiring, process network wiring, and control panel fabrication. Omni Instrumentation & Electrical Services, Inc., is certified in Foundation Fieldbus, Profibus, DeviceNet and ASI-Bus installation.