The most precise clamp-on meter available

The FLUXUS G736 gas flow meter combines highest precision digital signal processing with the well-known advantages of non-intrusive ultrasonic technology: ease of installation, retrofittable design, high accuracy, and outstanding performance. With 4 ultrasonic transducers operating in reflect mode, 8 independent ultrasonic paths traverse the gaseous medium providing superior flow averaging of up to 4 planes of the pipe section. With this configuration, the G736 flow meter averages out crossflow profile effects and achieves optimum non-intrusive flow compensation for undesirable installation locations where insufficient upstream straight pipe proximity to bends, elbows or other adjacent instrumentation creates flow disturbances.

FLEXIM integrated synchronized channel averaging leads to virtually no delay between the different channels and a highly synchronized, stable measurement result despite possible disturbed flow profiles.

On applications with longer straight runs, the 4-ultrasonic beam arrangement used with the G736 gas clamp-on flow meter achieves outstanding accuracy, performance, and repeatability, making it the preferred solution for redundancy measurement (check metering) of custody transfer meters, leak detection applications and allocation measurement where high accuracies are needed.

Even with shorter straight runs, the integrated disturbance correction provides a precise and highly repeatable measurement in a well-defined uncertainty range.

Furthermore, the meter automatically compensates for changing gas compositions and achieves accurate standard volumetric flow rate calculations with inputs from gas chromatographs, even under these challenging conditions.

Temperature compensated transducers, superior noise suppression and a highly rugged design offer an unrivalled degree of reliability, durability, and accuracy – ensuring perfect system operation under even the harshest field conditions.  The G736 gas flow meter is even suitable for underground installations (IP68 / NEMA 6P rated).

As close to Custody Transfer accuracy you can get from outside the pipe!

The G736 ultrasonic flow meter is capable of accuracy in the Custody Transfer class. By measurement principle, non-invasive ultrasonic flow meters exhibit some uncertainty related to pipe wall thickness and pipe geometry. However, these uncertainties are minimized with careful installation, precise pipe wall measurement and the inherent sensing capability of multiple 4-channel flow measurement. While intrinsic “out of box” custody transfer accuracy is not possible with clamp on metering, in many pipeline applications like check-metering, leak detection and others, it is possible to calibrate the G736 meter in-situ to achieve custody class accuracy (proven by industry independent calibration facilities – test reports are available upon request).

Accuracy is a topic we take very seriously because our clients expect us to over-perform and never disappoint. So, if you want to learn more about the total measurement uncertainty for your specific application, just ask us and we’ll be happy to advise.


  • High accuracy and repeatability – flow compensation – matched transducer pairs
  • Temperature compensated transducers – our transducers are automatically compensated for ambient temperature changes according to ANSI/ASME MFC-5.1-2011
  • Easy installation without process interruptions – retrofittable and compact design
  • Maintenance free – no moving parts, no wear and tear, gel/grease-free permanent transducer coupling pads
  • Operational safety – no leak paths, no direct contact with the fluid
  • Integrated synchronized channel averaging for perfect compensation of inhomogeneous flow profiles
  • FLEXIM Advanced Meter Verification provides you with detailed information about the meter health status at any time
  • Integrated disturbance correction
  • FLEXIM Dynamic Gas Master for compensation of changing gas compositions


Industry Applications

Technical Facts

Measurement uncertainty at the measuring point (volumetric flow rate)
± 1… 2 % of reading ±0.02 ft/s
Measurement uncertainty of the measuring system (volumetric flow rate)
± 1 to 3 % of reading ±0.02 ft/s
0.15 % of reading ±0.02 ft/s
Explosion protection
ATEX Zone 2
IECEx Zone 2 (certification in progress)
FM Class I Div. 2
Power supply
100-230VAC, 24DC, 12DC
Temperature Range (pipe wall)
-40°F to +392°F / WI: -328°F to +1166°F
Measuring quantities
Volumetric flow rate, mass flow rate, flow velocity, molecular mass, operational density, standard volumetric flow rate, caloric value
Flow channels
up to 4
4-20mA active/passive
4-20mA HART active/passive
4-20mA active/passive
Binary input
Digital communication
Modbus RTU
Foundation Fieldbus
Diagnostic functions
Sound speed, signal amplitude, SNR, SCNR, standard deviation of amplitude and transit time
Advanced Meter Verification (AMV)
Disturbance Correction
Synchronized Channel Averaging (SCA)
Additional Information
Transit time
Dynamic Gas Master (DGM)