1. Variable Gas Composition
   Biogas composition can vary depending on the feedstock and digestion process. Methane and carbon dioxide
   concentrations may change during operation, affecting gas density and volumetric measurement.
2. Moisture & Condensation
   Raw biogas can contain significant moisture. Condensation within the pipeline can result in unstable measurement and
   may affect instruments that are not designed for wet-gas service.
3. Hydrogen Sulphide
   H₂S can be corrosive and requires appropriate selection of wetted materials, seals and sensor construction.
4. Impurities & Particles
   Raw biogas may contain dust, residue and other contaminants that can cause fouling of sensing components.
5. Low & Fluctuating Flow
   Biogas production may vary significantly throughout the day. The flow meter should therefore have an appropriate
   turndown ratio and minimum flow capability.
6. Hazardous Area Considerations
   Since biogas can contain methane, the installation may require suitable explosion-protection / hazardous-area
   certification depending on the classified area and applicable project requirements.

01 | THERMAL MASS FLOW METER

Thermal mass flow meters measure gas mass flow directly and are particularly
suitable for applications where a wide flow range and low pressure drop are
required.

Typical Features:
 Direct mass flow measurement
 Wide turndown ratio
 Low pressure loss
 No moving parts
 Digital display option
 4–20 mA output
 Pulse output
 RS485 / Modbus communication options
 Insertion or inline construction
 316 / 316L wetted construction options
 Temperature and pressure compensation options
 Suitable hazardous-area versions available as required

Recommended Applications:
 Biogas header monitoring
 Anaerobic digester gas measurement
 CHP / generator gas consumption
 Boiler fuel gas monitoring
 Energy management

Important: Thermal mass flow meters should be selected based on gas
composition, moisture content, operating pressure and temperature.

02 | VORTEX FLOW METER

Vortex flow meters measure flow based on the frequency of vortices generated by a
bluff body placed in the flow stream.
They offer a robust solution for industrial gas measurement and can be considered
for relatively clean and stable biogas applications.

Features:
 No mechanical moving parts
 Robust industrial construction
 Suitable for gas applications
 Digital indication
 4–20 mA / pulse output options
 RS485 / communication options
 Temperature and pressure compensation options
 Flanged / wafer installation options

Applications:
 Treated biogas
 Biomethane
 Boiler gas
 Process gas monitoring
 Energy consumption measurement

03 | GAS TURBINE FLOW METER

Gas turbine flow meters use a rotating turbine element to measure gas velocity and
calculate volumetric flow.
They are suitable where good accuracy, repeatability and relatively clean gas
conditions are available.

Features:
 Good measurement accuracy
 Wide measurement range
 Low starting flow
 Digital totalization
 Pulse / frequency output
 Optional pressure and temperature compensation
 Compact construction

Applications:
 Treated biogas
 Biomethane
 Gas distribution
 Fuel gas monitoring
 Energy consumption measurement

04 | ROOTS / POSITIVE DISPLACEMENT GAS FLOW METER

Positive displacement gas meters measure a defined volume of gas through
mechanical displacement and are suitable for applications requiring reliable
volumetric measurement.

Features:
 Good low-flow performance
 Suitable for fluctuating gas demand
 High repeatability
 Mechanical or electronic totalizer options
 Corrosion-resistant construction options
 Pulse / electronic output options
 Suitable for gas consumption measurement

Applications:
 Biogas supply
 Gas consumption measurement
 Fuel gas monitoring
 Commercial / industrial gas metering
 Energy management

06 | V-CONE FLOW METER

V-Cone flow measurement is a differential-pressure technology designed to
condition the flow profile within the pipe.
It can be advantageous where installation space is restricted or conventional
straight-run requirements are difficult to achieve.

Features:
 Compact installation
 Robust construction
 Good repeatability
 Suitable for industrial gas applications
 Reduced straight-pipe requirement compared with conventional DP arrangements
 Suitable for demanding process environments

07 | ORIFICE FLOW METER

Orifice flow measurement is one of the most established differential-pressure
technologies used in industrial process measurement.

Features:
 Simple and proven technology
 Cost-effective
 No moving parts
 Suitable for large pipe sizes
 Easy integration with differential-pressure transmitters
 Available with various flange and pressure-class configurations

Consideration: Orifice meters can introduce permanent pressure loss and may
have a more limited turndown compared with some modern flow-meter technologies.