How the Rosemount 3051 Achieves High-Accuracy Flow Measurement

In process industries, flow measurement is one of the most critical variables for ensuring safety, efficiency, and profitability. Whether monitoring steam in a power plant, natural gas in a pipeline, or feedwater in a refinery, accurate flow data is essential for process control.

The Rosemount 3051 Pressure Transmitter, when paired with primary flow elements, has become a trusted solution for delivering high-accuracy flow measurement. Its design combines advanced sensor technology, digital intelligence, and modular integration to provide reliable results across a wide range of applications.

The Principle of Flow Measurement with Differential Pressure

The Rosemount 3051 measures flow using the differential pressure (DP) principle:

1. Primary Flow Element

• Devices such as orifice plates, Venturi tubes, or Annubar® averaging pitot tubes create a pressure drop as fluid passes through a restriction.

2. Differential Pressure Measurement

• The 3051 measures the pressure difference between the upstream (high-pressure) and downstream (low-pressure) sides.

3. Flow Calculation

• According to Bernoulli’s equation, the square root of the differential pressure is proportional to the flow rate.
• The transmitter’s microprocessor performs real-time compensation for temperature, pressure, and density to deliver accurate mass or volumetric flow.

How the Rosemount 3051 Ensures High Accuracy

1. Coplanar™ Platform Integration

• The patented Coplanar design allows seamless integration with primary flow elements and manifolds.
• Factory-assembled, leak-tested flowmeter assemblies reduce installation errors and improve measurement integrity.

2. Advanced Signal Processing

• The transmitter’s microprocessor applies temperature and static pressure compensation, correcting for real-world process variations.
• This ensures accuracy even in fluctuating conditions.

3. Wide Rangeability

• With turndown ratios up to 150:1, the Rosemount 3051 can measure both low and high flow rates with precision.
• This reduces the need for multiple devices across different ranges.

4. Integral Flow Solutions

• Emerson offers Rosemount 3051SFP Integral Orifice Flow Meters, which combine the transmitter with a precision-engineered orifice plate in a compact assembly.
• These assemblies achieve up to ±1.65% volumetric flow accuracy at 8:1 turndown.

5. Diagnostics and Digital Communication

• Built-in diagnostics detect plugged impulse lines, loop integrity issues, or abnormal process conditions.
• Supports HART®, FOUNDATION™ Fieldbus, PROFIBUS, and WirelessHART® for flexible integration and remote monitoring.

Real-World Applications

• Steam Flow in Power Plants – Accurate DP flow measurement ensures boiler efficiency and turbine protection.
• Natural Gas Distribution – High-accuracy measurement supports custody transfer and regulatory compliance.
• Chemical Processing – Precise flow control improves reaction yields and reduces waste.
• Water and Wastewater – Reliable flow monitoring ensures compliance with environmental standards.

Conclusion

The Rosemount 3051 achieves high-accuracy flow measurement by combining the proven differential pressure principle with advanced digital compensation, modular Coplanar™ design, and integrated flow solutions.

For industries that demand precision, safety, and efficiency, the Rosemount 3051 is more than a transmitter—it is a complete flow measurement platform that transforms raw process data into actionable insight.