Both electromagnetic and Coriolis meters are popular for liquid measurement. Here is how to choose between them.
Quick Decision Summary
Mag meters are lower cost, provide ±0.2-0.5% accuracy, create no pressure drop, require conductive fluids, and measure volumetric flow. Coriolis meters are higher cost, provide ±0.1% accuracy, create moderate pressure drop, work with any fluid, and directly measure mass flow and density.
Choose Mag Meters When
Measuring Water
Municipal water systems, wastewater treatment, irrigation, and cooling water are all ideal applications for mag meters. Water is conductive and typically does not require mass measurement.
Large Pipe Sizes
Coriolis meters become very expensive above 6 inches. Mag meters scale well to 48 inches and beyond, making them the clear choice for large pipe applications.
Slurries and Dirty Fluids
With no obstructions in the flow path, mag meters handle solids well. Ceramic liners resist abrasion, making them suitable for mining and mineral processing applications.
Budget is Limited
Mag meters are generally 40 to 60 percent less expensive than equivalent Coriolis meters. Installation and maintenance costs are also typically lower.
Choose Coriolis When
High Accuracy Required
For custody transfer, batch processes with tight tolerances, and high-value fluids, the ±0.1% accuracy of Coriolis meters is often necessary and justified by the value of the product being measured.
Mass Measurement Needed
When chemical reactions depend on mass ratios, billing is based on mass, or density compensation would be too complex, direct mass measurement with a Coriolis meter simplifies the process.
Non-Conductive Fluids
Oils, hydrocarbons, solvents, and deionized water cannot be measured by mag meters. Coriolis meters work with any fluid regardless of conductivity.
Density Information is Valuable
Coriolis meters provide simultaneous density measurement, which is useful for product quality monitoring, concentration measurement, and identifying products in multi-product pipelines.
Industry-Specific Guidance
Food and Beverage
Use mag meters for water and CIP (clean-in-place) solutions. Use Coriolis meters for the product itself such as milk, juice, and syrup where mass accuracy and density monitoring add value.
Chemical Processing
Use mag meters for water-based chemicals where conductivity is adequate. Use Coriolis meters for organic solvents and high-value chemicals where mass accuracy justifies the cost.
Oil and Gas
Coriolis meters are the standard for custody transfer in this industry. Mag meters are not suitable because oil is not conductive.
Cost Comparison
For a 2-inch line size, a mag meter typically costs $2,000 to $4,000 while a Coriolis meter costs $8,000 to $15,000. For a 6-inch line size, a mag meter typically costs $5,000 to $8,000 while a Coriolis meter costs $25,000 to $50,000. These are approximate figures and vary by manufacturer and specifications.