Gas flow measuring instruments

Your Benefits

  • Several standards and guidelines for flare gas measurement are observed
  • Maximum plant availability
  • Ultrasonic sensors, Interface Unit, Spool Piece from a single source as well as globally available services
  • Compatible with current and future communication architectures
  • Independent maintenance through verification on demand and support by SICK when required
  • Easy replacement of existing measurement systems, with suitable retrofit or upgrade solutions available

The exact device specifications and performance data of the product may deviate from the information provided here, and depend on the application in which the product is being used and the relevant customer specifications.
In accordance with Article 2 (4), this product does not fall within the scope of RoHS directive 2011/65/EU and is also not designed for use in products which fall within the scope of this directive. You can find additional information in the product information.


Precise and robust gas flow meter for flare gas or flare stack applications: Our ultrasonic gas flow measuring instrument FLOWSIC100 Flare-XT is designed for flare gas measurement or flare metering. The high-resolution measurement and innovative sensor design is being developed for most efficient uses in petroleum refineries, natural gas processing or offshore and onshore oil and gas plants. Emission control or monitoring, detection of flare gas leaks, steam flow measurement, monitoring of gas losses, monitoring of steam injection in flare gas burning, as well as process optimization and condition monitoring are fields of use for this gas flow meter. The gas flow meter is measuring values such as gas velocity, gas volume and mass, mass flow rate, molecular weight, volumetric flow a. c., volumetric flow s. c. and sound velocity. The flare gas flow meter provides an intelligent device monitoring process and supports predictive maintenance - designed for current and future challenges.

At a glance
  • Measurement availability under all operating conditions, at high gas velocities and with changing gas compositions
  • Intuitive FLOWgateTM operating software
  • I-diagnosticsTM for self-monitoring, easy verification and condition-based maintenance of the system
  • Retrofit solutions for existing measurement systems


Ultrasonic flow meter for flare gas applications

The FLOWSIC100 Flare-XT is characterized by its unique flow-optimized sensor design which enables reliable gas flow measurement and monitoring at extremely high velocities and changing gas compositions. Its rugged design guarantees an uninterrupted availability of measurements even under the most adverse conditions. FLOWSIC100 Flare-XT observes several applicable standards worldwide, and is suitable for use in new and existing plants. The measurement and diagnostic data can be visualized with ease using the FLOWgateTM software. Thanks to the intelligent i-diagnosticsTM function, the system is able to monitor itself and independently report the need for maintenance.

Flow Measurement with Ultrasonic transit time difference measurement:

Thanks to high-resolution sensors, the state-of-the art electronics precisely detects even very small transit time differences.

Flow Measurement with Ultrasonic transit time difference measurement:

The innovative, flow optimized sensor contour allows optimal measurement results even at very high gas velocities.

Flow Measurement with ASC-technology:

If the signal is blown away due to extreme gas velocity, the patented ASC-technology algorithm ensures uninterrupted measurement.

Accurate flare gas measurement in onshore and offshore facilities in the oil and gas, chemicals, petrochemicals, and refinery industries

Highly accurate data under extreme conditions such as gas velocities of 0 to 120 m/s (340 ft/s), rapid changes in the gas velocity and complex gas compositions.
Thanks to its innovative ASC-technology, FLOWSIC100 Flare-XT is now extending previous maximum flow range by up to 30%.

Precise flare gas measurement enables exact tracking of flare gas emissions

Powerful. Reliable. Robust.

FLOWSIC100 Flare-XT flare gas meter is available in three different versions. All versions are available as a 1- or 2-path measurement system. Cross-duct installation and single nozzle probe systems are available in either path configuration. The probe version is suitable for compact, one-sided fitting, which minimizes the installation work required. Both variants are available as a single or dual path measurement system. The 2-path version achieves high measurement accuracies even under difficult flow conditions. A device-retraction-mechanism also allows sensors to be replaced simply and quickly during plant operation. The powerful interface unit easily connects to a wide variety of systems and networks thanks to its numerous interfaces.

The Interface Unit processes incoming signals and calculates parameters, such as molecular weight, sound velocities, mass flow and gas volume, as well as standardized reference values.

Flare Instrument

Customer Application Framework:

  • Tapped pipe or unspecified spool piece geometry
  • Unknown or known application conditions


  • Easy retrofit of existing pipelines

Standard delivery scope:

  • Sensors + Interface Unit
  • Product and material certification

Optional delivery scope:

  • Performance capability evaluation
  • Customized documentation
  • Customer service training
  • I-diagnosticsTM

Applicable Installation equipment:

  • Weld-on nozzles
  • Nozzle installation tool
  • Ball valves
  • Optional: Weather and sun protection

1 Blue parts: SICK Scope of delivery

Flare Meter

  • With optional dry calibration or
  • With flow calibration

Customer Application Framework:

  • Flanged spool piece by SICK
  • Known application conditions


  • Easy installation without welding

Standard delivery scope:

  • Flare meter fully assembled
  • Product and material certification
  • Performance capability evaluation

Optional delivery scope:

  • Customized documentation
  • Customer service training
  • I-diagnosticsTM

Applicable Installation equipment:

  • Ball valves
  • Optional: Weather and sun protection

1 Blue parts: SICK Scope of delivery

2 Grey parts: Reference Meter

Ready for any situation thanks to leading ultrasonic technology

Sensors made of titanium and optimized for flare flow: The flow-optimized sensor design minimized turbulences and signal dispersion.
Thanks to interference-free, digital communication, the interface unit can be installed up to 1,000 m away from the measuring point. There is therefore no longer any need for a local, pressure encapsulated and potentially expensive control unit.
The FLOWSIC100 Flare-XT can be integrated effortlessly into existing plants. The system is compatible with existing FLOWSIC100 Flare installations. The interfaces are compatible with infrastructures already in place as well as future ones.

The powerful ultrasonic technology delivers reliable measurement also under extreme conditions during flaring.

Intelligent device monitoring and predictive maintenance

i-diagnosticsTM intelligently links software and firmware: The self-monitoring system delivers valuable data regarding the device status and highlights all changes. Application faults are immediately detected and documented, thereby time-consuming troubleshooting can be omitted. On request, the system verifies itself and records its current status. In this way, users have a very straightforward means of creating documents that prove that all emission regulations are fulfilled.

Simple maintenance. One-click verification. Self-diagnostics.

Predictive maintenance

Flexible service intervals The system continuously monitors performance parameters and generates reliable forecasts and maintenance recommendations based on this data.

1-click verification report

A report can be generated with one click for complete functional verification. This makes it easy to ensure and document compliance with legal requirements.


The intuitive FLOWgate software makes measurement, diagnostic and device data easier to handle, thereby permitting quick and uncomplicated system analysis.

The automatic verification of the measurement system and failure diagnostic reduces the number of service intervals and by that reduces maintenance costs.


Technical overview

  • Technical data overview

    Technical data overview

    Measured valuesMass flow rate, volumetric flow s. c., volumetric flow a. c., molecular weight, gas volume and mass, gas velocity, sound velocity
    Type of fieldbus integrationModbus TCP/IP
    FunctionCustomer interface, service interface
    Optical interface
    RemarkIR, according to IEC 62056-21
    FunctionService interface
All technical data can be found accompanying the individual product