Functional Safety approved Gas Flowmeter

The FLUXUS non-invasive ultrasonic gas flow meters have always been the first choice when it comes to maintaining accurate measurements in harsh conditions – e.g. during the flow measurement of highly pressurised, aggressive, toxic or highly explosive gaseous media.

FLUXUS measures from the safe side: From outside.

The clamp-on ultrasonic transducers are simply mounted on the outside of the pipe. Without any risk of leak and during ongoing operation. The ultrasonic measuring method doesn’t need any wetted devices, works independent of the pressure inside the pipe and is not subjected to mechanical stress which means it is practically wear-free.
As the wetted parts of inline measuring devices are not subject to the Failure Mode Effects and Diagnostics Analysis (FMEDA), they are not included in the scope of certification - presenting a safety risk. On the other hand, the SIL 2 certification of the FLUXUS non-invasive flow meter includes the entire measuring system -the measuring transmitters and transducers.

Safety without interruption.

The advantages of FLEXIMs non-invasive flow measurement technology pay off all the more over the entire lifecycle:
There is never any need to interfere with the pipeline system when carrying out periodic inspections. The self-diagnosis functions of the FLUXUS mean retests can be carried out easily to accurately assess the reliability and quality of the measurement. Even more detailed functional tests such as alarm tests or tests for monitoring compliance with measuring accuracy requirements never interfere with plant availability.


  • Non-invasive measurement without media contact
    • shortened prior-use method
  • Simple retrofitting during ongoing operation
    • ideal for a subsequent increase in safety
    • ideal for maintaining the protective function should an inline measurement fail
  • Comprehensive certification
    • transducers, clamp device and electronics are part of the FMEDA
  • Extremely wide range of applications
    • transducers and measuring transmitters for the flow measurement of gases
  • Straightforward retesting
    • easy functional tests in no time at all
    • convincing self-diagnosis functions
  • Transparent evaluations
    • publication of FMEDA report
    • full information on certification procedures and scope


Technical Facts

ATEX, IECEx Zone 2, FM Class I, Div. 1 approval (optional), IP66, aluminium or stainless steel housing variants
ATEX, IECEx Zone 1, FM Class I, Div. 1 approval, IP66, aluminium or stainless steel housing variants - suitable for offshore use
Measuring quantities
volume flow rate, mass flow rate, flow velocity
Operating temperature of the transmitter
-10 °C to +60 °C
Degree of protection
up to IP68
Temperature Range (pipe wall)
-40 °C to +100°C
Flow velocity range
0,01 to 35 m/s
Pipe diameter range
6 mm to 2100 mm (up to 35mm of pipe wall thickness)
Measurement accuracy
± 1 ... 3% of reading ± 0,01 m/s (dependend on application)
Measurement accuracy
± 0,5% of reading ± 0,01 m/s (field calibration)
0,15% of reading ± 0,01 m/s
Data logger capacity
>100 000 values: all quantities, summed measurings and diagnostics
Communication Protocol
Modbus RTU
Power supply
100 to 240 V AC / 50 to 60 Hz or 20 to 32 V DC
Additional Information