The PIOX S liquid mass flow meter determines the mass flow of liquids by means of clamp-on ultrasonic transducers mounted on the outside of the pipe. The non-invasive technology is the system of choice when substances and processes place highest demands on safety and reliability.
Conventional ultrasonic mass flow meters measure the volume flow of a medium and rely on a constant density or concentration of this medium to calculate the mass flow. In contrast the PIOX. dynamically infers the fluid’s density using its sound speed and temperature and therefore can provide mass flow in liquids of varying quality.

In binary liquids such as acids or sodas, the acoustic velocity is in a fixed proportion to concentration and density. This digital mass flow meter measures the sound velocity, thereby determining the density and concentration of the medium inside the pipe. It simultaneously records the volume flow rate using the transit time difference. From both values, after appropriate correcting for the current fluid temperature, the PIOX S mass flow sensor dynamically calculates the mass flow.

This makes the PIOX S the perfect alternative to the Coriolis mass flow meter. The non-invasive measurement of the PIOX S is not impacted by corrosiveness or abrasiveness of the liquid. No moving parts in the sensors, means drift-free measurement, making the PIOX S the top choice for the most challenging mass flow applications such as sulfuric acid, nitric acid, hydrofluoric acid and many more.


  • Fits all pipe sizes from ½” to 8”
  • For all pipe materials – glass, steel, plastic and more
  • For temperatures up to 400 °C
  • For pressure up to 3000 bar
  • For almost all acids, caustics and a wide range of other toxic liquids
  • For ATEX, IECEX and FM areas
  • No shut down for installation
  • Maintenance free


Industry Applications

Technical Facts

Measuring quantities
Mass flow
Measurement uncertainty (volumetric flow)
± 1 % of reading ±0.02 ft/s*
0,1 w%* (0,5m/s)
Flow velocity range
0.03 to 82 ft/s
Ex zone transmitter
ATEX/IECEx Zone 1/Zone 2
FM Class I - Div2
Power supply
100-230VAC, 24DC, 12DC
Available transducers
Shear wave
for Ex zones
ATEX/IECEx Zone 1/Zone 2
FM Class I - Div2
for pipe sizes range
0.24 inch to 255.9 inch
for temperature range
-40°F to +392°F / WI: -328°F to +1112°F**
4-20mA active/passive
4-20mA HART active/passive
4-20mA active/passive
Binary input
Digital communication
Modbus RTU/TCP
Profibus PA
Foundation Fieldbus
Additional Information
For more detailed Information please download the Technical Specifications
* For most waterbased solutions and common working point
** additional wave injector required