High-performance measuring turbines for hydraulic systems

Our high-precision measuring turbines enable a second-by-second analysis of volume flows, even when different hydraulic fluids are used under high pressure.

Precise and reliable flow measurement for hydraulic systems

Hydraulic measurement technology places special challenges on the components used. As a solution for these requirements, the measuring turbines from DDM Sensors, such as the VCT-AN and FLT model series, offer precise and reliable flow measurement. The core advantages of these systems lie in their

• high accuracy,
• robust longevity, and
• uncomplicated system integration into existing and new hydraulic systems.

Technical specifications of measuring turbines for hydraulics

Feature	Model FLT	Model VCT-AN
Measuring ranges	0.06 to 1200 l/min	0.06 to 1200 l/min
Nominal widths	3/8″ to 2″ (or AN8 to AN32)	AN8 to AN32 (inner-Ø 6.8 to 45.2 mm)
Process connections	Thread (AN8 to AN32; M18 to M52), Ermeto EO cutting ring (DIN 3861), AN thread 37° flare (ISO 8434-2)	Threaded connection (AN8, AN10, AN12 to AN32 on request)
Materials	High-performance hybrid ball bearings with ceramic balls and stainless steel cages	High-performance hybrid ball bearings with ceramic balls and stainless steel cages
Viscosity ranges	Works viscosity-independently in combination with flow computers (VCA/VCA-T/VCA-CAN)	Works viscosity-independently in combination with flow computers (VCA/VCA-T/VCA-CAN)
Pressure levels	High pressure up to 500 bar depending on size	25 bar max., others on request
Temperature ranges	Medium: -40 to +150°C; Ambient: -40 to +125°C Special forms up to 200°C available	Medium: -40 to +150°C; Ambient: -40 to +125°C
Output signals	TTL signal (turbine frequency max. 2 kHz)	TTL level (turbine frequency max. 2 kHz)

Operating conditions and media compatibility

The measuring turbines are designed for use with all common hydraulic media, including hydraulic oil, HLP/HVLP, and bio-oils. They can either be calibrated to a specific viscosity according to customer requirements or, in combination with a flow computer, work viscosity-corrected in a wide range from 1 to 1000 mm²/s working.

In the event of temperature fluctuations and unclear media properties, DDM can perform a viscosity determination in the range of -40 to 120 °C carry out. Depending on the series, the turbines are designed for a continuous operating pressure of up to 500 bar designed. The construction takes into account the sensitivity to typical hydraulic phenomena such as pulsation, cavitation, and pressure surges.

Mechanical properties and integration

Thanks to integrated flow rectifiers at the inlet and outlet, long inlet and outlet sections can be avoided. The pressure loss at high volume flows can be calculated for each specific working range.

High-performance hybrid ball bearings with ceramic balls, which have excellent emergency running properties and enable a long service life with particle-free oil, ensure a long service life.

Electrical interfaces and system compatibility

Various electrical signal outputs are offered for system integration, including a TTL pulse signal and analog outputs for current (4–20 mA) and voltage (0–10 VDC). PNP/NPN and frequency outputs are also available. Digital communication is realized via a CAN-BUS interface. This ensures seamless compatibility with common PLC controls and test stand systems.

Application areas in hydraulic system monitoring

The measuring turbines are suitable for a variety of monitoring tasks in hydraulic systems. These include

• Leakage and efficiency measurements to create pump characteristics and to determine volumetric efficiency. They are used for monitoring both constant and variable displacement pumps.
• Detection of deviations from the target volume flow as well as precise volume flow measurement as an input variable for closed-loop control.

Application-specific measuring turbines for hydraulics

For special solutions, DDM Sensors also develops application-specific measuring turbines. This includes the adaptation of geometry and materials as well as the realization of customer-specific mechanical and electrical interfaces.

Thus, projects with special thread geometries, sensors for extended temperature ranges up to 200 °C or adaptations for exactly defined installation spaces, for example for direct flow measurement in the transmission, have already been implemented.

The process ranges from prototype construction to subsequent series production..

Availability, delivery and technical support

The measuring turbines are available in series and can be delivered within 3 weeks. In addition to the measuring turbines, DDM Sensors supports with comprehensive technical support, which includes the design and dimensioning of the turbine, help with error analysis, as well as direct contact with the in-house expert team.

Get advice on measuring turbines for hydraulic applications now

Request a non-binding technical consultation for your specific application and find the optimal solution together with the experts from DDM Sensors.