EMS-FLOW-STAR-U – Next-generation ultrasonic volume measurement technology
Meet the highest metrological requirements in complex heating and cooling infrastructures with the EMS-FLOW-STAR-U ultrasonic flow-measuring unit:
In today’s world, where the energy optimization of infrastructure is a top priority, precise flow measurement serves as the foundation for any professional energy management system. The EMS-FLOW-STAR-U ultrasonic flow sensor was developed to meet the most rigorous measurement standards in complex heating and cooling infrastructures. By utilizing advanced ultrasonic technology, the EMS-FLOW-STAR-U overcomes the limitations of conventional mechanical meters, offering a future-proof platform for thermal energy metering—whether in extensive district heating networks, local heat supply systems, or demanding industrial process cooling circuits.
The physical operating principle of the EMS-FLOW-STAR-U ultrasonic volume measuring unit
The core component of the EMS-FLOW-STAR-U is a high-resolution, dual-channel ultrasonic measurement system based on the transit-time principle. Unlike conventional impeller or Woltman meters—which measure flow using a mechanical component that obstructs the flow of the medium—the EMS-FLOW-STAR-U presents no mechanical barrier.
This has a profound impact on operational efficiency: the absence of mechanical components completely eliminates the wear on bearings and gears that is inevitable in mechanical meters. This technological advantage ensures consistent measurement accuracy throughout the entire calibration period.
Certification under the European Measuring Instruments Directive 2014/32/EU (MID)—specifically Accuracy Class 2 according to EN 1434—confirms the high precision and reliability of the EMS-FLOW-STAR-U ultrasonic sensors.
Furthermore, EMS-FLOW-STAR-U units meet the rigorous mechanical requirements of Class M2 and the electromagnetic requirements of Class E2 (per EN 1434), guaranteeing reliable operation in demanding industrial environments.
Dimensionierung, Flexibilität und physikalische Einsatzgrenzen des Ultraschall Volumenmessteils EMS-FLOW-STAR-U
The design of the EMS-FLOW-STAR-U ultrasonic volume measuring unit is geared towards maximum application versatility in order to meet the diverse requirements of modern building and process control technology.
• Scalability of nominal diameters: The system is available in a size range from DN 50 to DN 300, covering flow rates (Qp) from 15 m³/h up to 600 m³/h. This enables the implementation of projects ranging from small transfer stations to large industrial distribution hubs using a unified technology.
• Temperature management: The flow measurement unit is specified for a medium temperature range of 1°C to 130°C. For thermal stress scenarios—such as system maintenance or thermal disinfection cycles—the device is designed to withstand temperatures up to 150°C for short-term operation of up to 2,000 hours.
• Pressure resistance: Depending on the specific system design, certifications for PN 16 or PN 25 pressure classes are available, allowing for safe integration into high-pressure heating networks.
• Geographic and climatic robustness: The devices are designed for ambient temperatures between 5°C and 55°C and remain fully functional at relative humidity levels of up to 95%. Measurement accuracy is maintained even in extreme environments, with an IP68 rating ensuring complete protection against moisture ingress. Unrestricted operation is permitted at altitudes of up to 2,000 meters above sea level, while safe storage and transport are possible at temperatures ranging from -25°C to 55°C.
Signal processing, interface technology and system connection of the EMS-FLOW-STAR-U ultrasonic volume measuring unit
The EMS-FLOW-STAR-U ultrasonic flow sensor functions as a high-precision flow measurement component within a larger energy metering system. Communication with a higher-level calculator takes place via an open-collector pulse output standardized in accordance with EN 1434-2.
The pulse output of the EMS-FLOW-STAR-U ultrasonic volume measuring unit (in accordance with EN 1434-2)
To ensure reliable signal transmission, the EMS-FLOW-STAR-U ultrasonic volume measuring unit is optimized for a minimum pulse duration of 50 milliseconds. Electrically, the EMS-FLOW-STAR-U is designed for a maximum input voltage of 12 V DC and a maximum input current of 10 mA for volume pulses. The connection between the EMS-FLOW-STAR-U volume measuring unit and the measuring unit is established via an included, pre-assembled 10-meter cable, enabling flexible and professional installation in the immediate vicinity of the measurement point.
Energy supply and maintenance strategy for the EMS-FLOW-STAR-U ultrasonic volume measuring unit
The frequency of maintenance interventions is a critical factor in the cost-effective operation of metering infrastructure. The EMS-FLOW-STAR-U ultrasonic volume measuring unit addresses this issue through a highly optimized power supply system. Its autonomous power supply, provided by a 3.6 V lithium battery, enables an operating life of up to 12 years. This duration aligns with the statutory calibration periods for heat meter components, thereby virtually eliminating the need for maintenance—with the exception of the mandatory calibration replacement intervals.
Installation, commissioning, and operational safety
The installation of the EMS-FLOW-STAR-U is to be understood as a process that adheres to strict technical standards in order to maintain the integrity of the metrological data acquisition.
• Preparation: Before commissioning, the pipeline must be flushed to remove foreign objects or deposits. During installation, particular attention must be paid to the direction of the medium’s flow. The specified flow direction is easily identified by the arrow stamped on the meter housing. This point is of great importance, as reverse installation leads to significant measurement errors.
• Hydraulic aspects: To protect the system against water hammer, the sequence in which the shut-off valves are opened and closed is critical: the valve upstream of the metering unit must be opened slowly before the shut-off device downstream of the meter is operated.
• Special installation situations: For vertical mounting, the installation must be arranged so that the water flows from bottom to top to ensure the measuring tube remains completely filled. In the case of U-shaped piping layouts, the device must be positioned at the lowest point of the U-bend so that air pockets are removed via buoyancy and do not affect the sensor system.
• Legal Compliance: All seals applied at the factory to protect calibration-relevant data must remain intact. Any damage will inevitably void the validity of the calibration and the manufacturer’s warranty.
• Handling electronics: The lithium technology used in the built-in batteries requires careful handling. Exposure to temperatures above 80°C, short circuits, or mechanical opening of the battery unit is prohibited. Likewise, welding work in the immediate vicinity of the installed unit must be avoided, as inductive coupling or heat generation can cause irreparable damage to the internal electronics.
Adherence to AGFW recommendation FW-510 and VDI 2035 regarding water quality ensures that the measurement stability of the EMS-FLOW-STAR-U is maintained throughout its entire service life. With its robust EMC compliance, the EMS-FLOW-STAR-U ultrasonic volume measuring unit ensures precise, interference-free operation even in industrial environments subject to high levels of electrical or magnetic interference.
