E&H 9B2B ultrasonic flowmeter

E&H 9B2B ultrasonic flowmeter

Introduction: The Specialist for Wet Biogas Measurement

The Endress+Hauser Proline Prosonic Flow B 200, designated under the product root 9B2B, represents a paradigm shift in biogas flow measurement. Designed specifically for the harsh realities of wet biogas, digester gas, and landfill gas applications, this ultrasonic flowmeter delivers accurate, reliable performance even under severely fluctuating process conditions.–35

What distinguishes the E&H 9B2B ultrasonic flowmeter from conventional gas flow metering solutions is its loop-powered architecture and unique ability to measure not only volume flow but also methane fraction in real time. For operators of anaerobic digesters, wastewater treatment plants, and biogas upgrading facilities, this multivariable capability transforms a simple flowmeter into a powerful process optimization tool.-

Key Technical Specifications at a Glance

Accuracy Specifications:

Volume flow (standard): ±1.5% o.r. for 3–30 m/s; ±3% o.r. for 1–3 m/s

Volume flow (optional): ±0.1% o.f.s. for 0.3–1 m/s; ±1.5% o.r. for 1–30 m/s

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Five Sub-Models: Understanding the 9B2B Product Family

The E&H 9B2B ultrasonic flowmeter series comprises five distinct product variants, each tailored to specific pipe diameters and application requirements. Understanding these sub-models is essential for correct device specification.

9B2B50 – DN 50 (2″) Single-Path Configuration

The 9B2B50 represents the smallest nominal diameter offering in the B200 series, designed for DN 50 pipelines (2-inch). This compact variant is ideal for smaller biogas lines, pilot-scale digesters, and applications where space constraints demand a minimal footprint. Despite its size, the 9B2B50 delivers the full multivariable measurement capability of the series: volume flow, temperature, and optional methane fraction analysis.-46

9B2B80 – DN 80 (3″) Single-Path Configuration

The 9B2B80 serves the DN 80 (3-inch) market segment, offering the same single-path ultrasonic measurement technology as its smaller sibling but scaled for moderate flow rates. This configuration is frequently specified for medium-sized anaerobic digesters and biogas collection headers where line sizes fall between 2 and 4 inches.-46

9B2B1H – Two-Path High-Performance Configuration

The 9B2B1H introduces two-path ultrasonic measurement technology, delivering enhanced accuracy and redundancy for DN 100 to DN 200 pipelines (4 to 8 inches). The dual-path configuration improves measurement performance in challenging flow profiles, making the 9B2B1H particularly suitable for main biogas headers and larger digesters where flow conditions may be less than ideal.-2

9B2B1F – Two-Path Flanged Configuration for DN 150

The 9B2B1F is specified for DN 150 pipelines (6-inch nominal diameter). This two-path variant combines the accuracy benefits of dual-path technology with flanged process connections for secure, leak-free installation. A typical ordering example is 9B2B1F-C2ACCD1A121, which has been documented as a stocked configuration with a manufacturer list price of $11,158.79.-11-42

9B2B2H – Two-Path High-Performance for DN 200

The 9B2B2H represents the largest offering in the B200 series, engineered for DN 200 pipelines (8-inch nominal diameter). This two-path configuration is designed for high-volume biogas applications, including centralized collection systems, biogas upgrading plants, and landfill gas extraction networks. A documented configuration, 9B2B2H-NJBECB1D211+AK, specifies a DN 150 measuring range of 22.9 to 2,289.75 m³/h for biogas service under micro-negative pressure conditions.-

Complete Order Code Breakdown: 9B2B50-AAACCD1A141+AA

Endress+Hauser utilizes a highly structured order code system that encodes all device features and options into a compact alphanumeric string. Understanding this structure enables engineers and procurement specialists to verify configurations, order spare parts, and ensure specification compliance.

Below is a detailed breakdown of the order code 9B2B50-AAACCD1A141+AA:

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When ordering or verifying device configurations, users can enter the complete order code into the Endress+Hauser W@M Device Viewer (www.endress.com/deviceviewer) to retrieve full documentation, spare parts lists, and device-specific information.-

Core Technology: Why Ultrasonic Transit Time for Biogas?

The Prosonic Flow B 200 operates on the ultrasonic transit time principle. Two ultrasonic sensors are mounted on opposite sides of the measuring tube at a specific angle. The flowmeter transmits ultrasonic signals alternately in both directions—upstream and downstream. The transit time of the signal traveling with the flow is shorter than that of the signal traveling against it. This time difference (Δt) is directly proportional to the average flow velocity.-46

What makes this principle revolutionary for biogas applications is its immunity to gas composition variations. Unlike thermal mass flowmeters or differential pressure devices, the ultrasonic measurement principle remains unaffected by changes in gas composition, moisture content, or pressure fluctuations. The E&H 9B2B ultrasonic flowmeter delivers reliable readings regardless of whether the biogas contains varying levels of methane, carbon dioxide, hydrogen sulfide, or water vapor.-35-12

Integrated Real-Time Methane Fraction Analysis

Perhaps the most compelling feature of the E&H 9B2B ultrasonic flowmeter series is its ability to measure methane concentration (CH₄ fraction) in real time without additional analyzers. The underlying physics is elegant: the speed of sound in a gas is a function of its temperature and molecular composition. The Prosonic Flow B 200 precisely measures both the speed of sound and the gas temperature, then calculates the methane fraction directly.-46

Given that biogas is typically saturated at 100% relative humidity, temperature measurement also enables moisture content determination and compensation. This capability provides continuous 24/7 monitoring of both gas quantity and gas quality, allowing plant operators to respond rapidly to process disturbances in the digestion process.-46

Measured multivariable outputs:

Volume flow

Corrected volume flow

Corrected methane volume flow

Energy flow

Methane fraction

Calorific value

Temperature

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Heartbeat Technology: Integrated Verification

Endress+Hauser’s patented Heartbeat Technology is embedded within the 9B2B series, providing continuous self-diagnostics and on-demand verification without process interruption. This capability enables:

Continuous self-monitoring of sensor and electronics health

On-demand verification of meter accuracy against factory specifications

Documentation-ready reports for regulatory compliance and quality audits

Predictive maintenance alerts before failures occur

For biogas plant operators subject to emissions reporting, carbon credit verification, or renewable energy incentive programs, Heartbeat Technology provides the auditable traceability required for compliance while eliminating costly off-line calibration.-1-10

Design Advantages for Low-Pressure Gas

Biogas systems typically operate at low pressures—often between 0.7 and 11 bar absolute (10.2 to 159 psi). Many conventional flow measurement technologies struggle under these conditions, but the E&H 9B2B ultrasonic flowmeter has been specifically optimized for low-pressure gas service.

Specialized sensor design for low pressure ensures accurate measurement even when line pressures drop near atmospheric levels. The full-bore design creates no additional pressure drop, preserving precious energy in the biogas system. This is particularly critical in applications where biogas is used directly for boiler fuel or engine generation, as any pressure loss directly impacts energy yield.-10-2

Loop-Powered Technology: Simplified Installation

The 9B2B series operates on loop-powered two-wire technology, drawing all necessary power from the 4-20 mA HART current loop. This design philosophy delivers several practical benefits:

Reduced wiring costs compared to four-wire instruments

Simplified integration into existing control systems

Intrinsic safety compatibility for hazardous area installations

Lower installation labor requirements

The B 200 is certified for intrinsically safe operation in Class 1 Division 1 and other hazardous areas, with ATEX, IECEx, and CSA approvals available. A second 4-20 mA output can be configured for simultaneous transmission of flow rate and methane fraction.–12

Practical Application Case Study: $72,500 Annual Savings

The City of Reading, Pennsylvania, USA, implemented the Prosonic Flow B 200 to optimize its anaerobic digester operations. Prior to installation, the plant relied on outdated pressure transducers that produced inaccurate readings, combined with manual temperature monitoring requiring up to four hours of technician time daily.-36

Results achieved with the E&H 9B2B ultrasonic flowmeter:

Labor savings: Approximately $20,000 per year

Tear-down maintenance: Reduced by 50%, saving $15,000 annually

Fuel cost reduction: Average savings of $37,500 per year

Total annual savings: $72,500

The B 200 provided real-time, multipoint data on flow rate, temperature, and methane fraction, enabling operators to maintain digester parameters within optimal ranges. When methane fraction would previously drop below 20% or temperature fall to 80°F, the plant was forced to tap external natural gas at costs up to $16,000 per month—a scenario eliminated by the continuous monitoring capability of the 9B2B series.-36

Environmental and Operating Conditions

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Installation and Commissioning

The E&H 9B2B ultrasonic flowmeter is designed for straightforward installation with minimal upstream straight-run requirements. The separate connection compartment allows convenient device wiring without exposing internal electronics to the environment.-5

Commissioning features:

Seamless system integration via HART protocol

Guided parameterization with “Make-it-run” wizards

HistoROM for automatic data backup

Life Cycle Management (W@M) support

The touch-controlled illuminated display eliminates the need to open the device during operation, enhancing safety and maintaining environmental protection.-10-5

Model Comparison Summary