Flow Measurement​

Flow measurement is the quantification of how much liquid, gas, or steam moves through a pipe or process system. Accurate flow measurement is critical for maintaining process control, ensuring product quality, optimizing energy use, and meeting safety and regulatory requirements across industries such as oil and gas, chemical, water and wastewater, life sciences, power generation, metals and mining, marine, refining, and more.​

The right flow meter depends on several key factors, including fluid type, required accuracy, process conditions, and installation constraints.​

• Coriolis flow meters are ideal for high-accuracy mass flow and custody transfer​
• Magnetic flow meters perform best in conductive liquid applications such as water and slurry​
• Differential pressure (DP) flow meters are widely used for steam, gas, and legacy installations​
• Vortex flow meters are well suited for steam and clean gas measurement​
• Ultrasonic flow meters offer non-intrusive or high-precision measurement for liquids and gases​

Evaluating these variables ensures the selected technology delivers reliable performance and long-term value.​

Each flow measurement technology uses a different principle to measure flow:​

• Coriolis measures mass flow directly using tube vibration​
• Magnetic measures volumetric flow based on fluid conductivity and electromagnetic induction​
• Differential pressure (DP) calculates flow from pressure drop across a primary element​
• Vortex detects vortices shed by the flowing fluid to determine velocity
• Ultrasonic uses sound waves to measure flow velocity, either inline or non-intrusive​

These differences affect accuracy, maintenance requirements, pressure loss, and suitability for specific applications.​

Non-intrusive ultrasonic flow meters are ideal when process interruption is not feasible or when avoiding pipe penetration is a priority. They are commonly used for temporary measurements, energy audits, retrofit installations, or hazardous environments where minimizing installation complexity and downtime is critical.​

Coriolis flow meters are typically preferred for high-accuracy applications because they measure mass flow directly and provide exceptional repeatability and stability. They are widely used in custody transfer scenarios where measurement precision directly impacts financial transactions and regulatory compliance. ​

Key process conditions that influence flow meter selection include:​

• Fluid type (liquid, gas, steam, slurry, multiphase)​
• Temperature and pressure range​
• Flow rate and pipe size​
• Fluid properties such as viscosity, density, and conductivity​
• Presence of solids, bubbles, or contaminants​

Understanding these conditions helps ensure accurate measurement and avoids performance issues over time.​

Modern flow measurement technologies are designed to perform reliably in demanding environments, including high pressure, extreme temperatures, corrosive media, and multiphase flow conditions. Advanced diagnostics, durable materials, and application-specific designs help maintain accuracy, reduce maintenance, and improve operational uptime.​

Accurate, real-time flow data enables operators to optimize control strategies, reduce waste, improve yield, and identify performance issues before they lead to downtime. When integrated with digital systems, flow measurement also supports predictive maintenance and data-driven decision-making across the plant.​

Selecting the optimal flow measurement technology can be complex, but the right tools and expertise make the process easier. Emerson provides application expertise, engineering tools, and digital selection platforms to help evaluate your requirements and recommend the best solution for your process.​