Fluid Analysis - Fluid Identification

Every liquid has specific acoustic properties. By measuring how fast an ultrasonic signal travels through the medium, our sensors can detect changes in the liquid and correlate the measured speed of sound with its composition.

This makes ultrasonic technology more than a flow measurement principle. It can also provide valuable information about what liquid is flowing and whether its composition is within the required range.

Liquid Detection

When two liquids have sufficiently different acoustic properties, their speed of sound can be used to distinguish between them. This enables reliable fluid identification without requiring optical measurement or additional components in contact with the medium.

A practical example is coffee machines and beverage dispensers. Our technology can detect whether the correct cleaning liquid is being used during a cleaning cycle and distinguish it from water or the normal beverage medium. It can also help differentiate between different syrups and beverage components, supporting correct dosing and process control.

For more complex applications involving three or more fluids, detection can become more challenging when two liquids have similar speeds of sound. In these cases, application-specific calibration and sensor configuration can be used to achieve reliable detection.

Mixing Ratio Monitoring

Speed of sound can also be correlated with the concentration of a mixture. This allows Allengra sensors to continuously monitor whether a defined mixing ratio is being maintained.

A typical example is water-glycol mixtures, where maintaining the correct concentration is important for system performance. The sensor can continuously monitor the mixture and detect deviations from the target ratio, helping identify incorrect dosing, contamination or changes in the fluid composition.

This principle can be applied wherever a process depends on a consistent fluid composition, providing continuous, real-time monitoring without interrupting the flow.

One Measurement, More Information

By combining ultrasonic measurement with speed-of-sound analysis, Allengra sensors can provide more than flow data. They can help determine which liquid is present, detect changes in composition and monitor mixing ratios, opening new possibilities for intelligent and compact OEM solutions.

The speed at which sound travels through a gas changes with its composition. By analysing these acoustic properties, Allengra sensors can determine the concentration of individual components in a gas mixture while simultaneously providing flow information. This makes ultrasonic technology a powerful tool for both gas flow measurement and composition monitoring.

Hydrogen & Nitrogen

One of the key applications is hydrogen/nitrogen analysis in PEM fuel-cell anode recirculation.

During fuel-cell operation, excess hydrogen can be recirculated from the anode outlet back to the stack inlet instead of being wasted. At the same time, nitrogen can accumulate in the anode gas and negatively affect stack operation. Monitoring the gas composition and the hydrogen/nitrogen ratio helps optimize recirculation and purge strategies.

Allengra’s Hydrogen Flow Meter uses ultrasonic technology to determine gas composition and supports mixtures such as H₂/N₂/H₂O. Integrated temperature, pressure, and humidity sensors enable additional measurement of density and mass flow. The sensor is designed specifically for applications including PEM fuel-cell anode inlet and recirculation, electrolyzers, hydrogen production, and industrial process monitoring.

Gas Mixing Ratio

The same principle can be used to monitor the composition of other gas mixtures. Allengra’s technology can analyse mixtures such as hydrogen and nitrogen or hydrogen and methane, with the ultrasonic signal providing information about changes in gas composition.