Ultrasonic water meter
Static ultrasonic water meters are the future of water network management. WaterTech makes ultrasonic water meters with innovative construction solutions that are unique in the market: the accuracy and reliability of ultrasonic technology are combined with physical and structural features that improve measurement and lower network management costs.
Static ultrasonic technology has revolutionized the metrology industry and offers several advantages over traditional turbine or piston meters. Ultrasonic water meters are now indispensable for the management of such a precious resource as water. Not only that, but they are also essential for optimizing the consumption and energy costs of water networks.
This is because of their inherent characteristics:
⋅ Precise measurement that remains unchanged over time. The absence of mechanical moving or rubbing parts inside the meter body zeroes out the possibility of wear and tear and deterioration of measurement accuracy over time.
⋅ Absolute ability to measure exactly all the water passing through the pipe. Ultrasonic technology can detect even the smallest water flows (the low flow rates that traditional mechanical meters cannot count) and micro-leaks, the so-called NRW (Non-Revenue Water).
⋅ Ability to measure the flow in both directions with great accuracy. An indispensable function for monitoring large nodes of water networks and managing them efficiently, detecting any anomalies.
⋅ Possibility of installation in all positions while maintaining measurement accuracy.
⋅ Legal lifespan of 13 years, compared with 10 years for traditional mechanical meters.
⋅ Ability to work effectively even with water of different hardness. Static ultrasonic meters are indifferent to the different possible physicochemical characteristics of the water and therefore manage to work perfectly, guaranteeing maximum accuracy, regardless of the hardness of the water, its conductivity, and the presence of suspended solid particulate matter (even within the same network, there can be significant differences in the chemical and physical properties of the water as the area or conditions of the sampling wells vary).
Because of these significant advantages, the ultrasonic smart meter is the ideal measurement tool to serve as the foundation of the smart metering chain, initiate the digitization of smart metering networks, and implement strong loss reduction.
HOW AN ULTRASONIC WATER METER WORKS: THE PRINCIPLE OF TRANSIT TIME
The operation of the ultrasonic meter is based on the propagation of sonic pulses traveling through a fluid. Clearly, each fluid family has its own specific sonic wave propagation speed. This is a constant that indicates the speed at which the wave moves within that particular fluid under static, i.e., non-moving, conditions. Ultrasonic water meters are, as the name implies, parameterized on the speed of ultrasonic propagation in water.
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Exactly as is the case when you are in a canoe and trying to cross a river, depending on whether you are paddling against or against the current, the transit time is different; longer if you are paddling against the current, shorter if you are paddling with the current in your favor. This is how the principle of transit time works.
Two piezometric transducers are inserted inside the measuring tube at a predetermined distance, which alternately emit an ultrasonic wave and receive the wave produced by the twin piezo sensor. In the case where there is no fluid movement, the transit time of the two waves is identical. On the other hand, in the case where there is flow, the wave moving in the same direction as the flow will be accelerated, while the wave moving against the flow will be slowed down. The higher the velocity of the water flow, the greater the slowing and acceleration of the two ultrasonic signals will be.
In practice, the time taken by the ultrasonic wave to go from the first transducer to the second and vice versa is affected by the direction of the flow and involves 2 travel times, T1 and T2, the difference of which, called ΔT, is directly proportional to the velocity of the flow. This means that it is sufficient to know the diameter of the measuring tube (which, clearly, is well known) to be able to determine the volume of water flowing.
The wave path can take different configurations: from the simplest V-shape to the most complex Z-shape. WaterTech has opted for a Z-shaped path, which, therefore, involves two mirrors positioned to the side of the two piezometric sensors (as observable in the video). Such a configuration makes it possible to lengthen the path that each individual ultrasonic wave must take to reach the receiving transducer. A longer path leads as a direct consequence of an increase in the time differential between the two opposite wave paths.
This, in turn, is reflected in the higher accuracy of the meter measurement. Thanks to such an ingenious system, WaterTech’s range of ultrasonic residential water meters manages to achieve an accuracy class of up to R800; this is a distinctly remarkable achievement, as only very few other ultrasonic meters can boast similar performance.
OPTIMIZING WATER NETWORK MANAGEMENT WITH ULTRASONIC WATER METER
In addition to top-notch ultrasonic technology, WaterTech has studied every aspect of the static smart meter, making true engineering gems applied to water metering. Today, the two static water meters SONATA and OCTAVE are the best solutions for residential or industrial users on the market.
Drawing on the collaboration of the highly advanced Israeli parent company ARAD, WaterTech offers ultrasonic water meters with outstanding performance. Born from the combination of Israel’s most sophisticated water measurement technologies (for which ARAD is the almost total supplier) and WaterTech’s in-depth knowledge of the water distribution sector in Italy, the latest generation of ultrasonic electronic static water meters, SONATA and OCTAVE represent the cutting edge in the field of management of the precious water resource.
What makes them unique are:
- Extremely high measurement accuracy (up to R800), even at the lowest flow rates.
- Sensors positioned at the centerline of the measuring pipe, on a horizontal plane (and not at the bottom and on a vertical plane, as is the case in most cases), so as not to create obstructions and avoid the formation of deposits and sediment, thus ensuring that excellent performance is maintained throughout the meter’s legal life.
- Available with either a brass body or a composite body (a highly reinforced technical thermoplastic with high percentages of fiberglass, widely used in aerospace applications), i.e., materials that are solid, strong, and capable of lasting.
- Native equipment with all commercially available transmission systems.
- No need to create straight sections of pipe upstream and downstream of the meter (U0D0), which makes these meters suitable for any type of installation.
- Availability of the full range, from DN15 to DN300.
- Presence of dual circuit and dual power coils.
- Subject to very low pressure drop, resulting in significant savings of electricity by the operator and reduced risk of pipe rupture.
Ultrasonic static vacuum tube water meters: perfect measurement and energy saving
WaterTech ultrasonic meters are currently the only electronic ultrasonic static water meters available on the market that combine very high measurement accuracy and very low pressure drop.
Ultrasonic technology performs best when the flow of water passing through the meter is particularly fast. Many commercially available solutions, to compensate for less-than-stellar metrological performance, exploit a physical principle called “Venturi tube,” creating a bottleneck near the piezometric sensors to increase the transit velocity through the meter tube and improve the quality of the meter measurement. This, however, has a heavy downside: the bottleneck inside the tube causes a reduction in flow rate and a consequent drastic increase in pressure loss.
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This has huge impacts for utilities because pumps, which regulate flows within a water network, must work harder to ensure the same flow rate. Since they are powered by electricity, this translates into heavier bills for the utilities. In addition, an increase in the power usage of the pumps is reflected in an overall increase in the pressure of the network itself, resulting in a significant increase in the risk of pipe rupture and resource loss.
The unique full vacuum tube construction with which WaterTech’s ultrasonic water meters are designed allows them to boast extremely low ΔP (pressure loss due to the passage of water through the instrument). The SONATA electronic static meter even has a ΔP of only 0.16 bar (most other products on the market have pressure losses of 0.40 or 0.64 bar). This particularly ingenious technical device, the result of Israel’s great know-how in the field of water saving, makes it possible to reduce the pressure within the water network by as much as half a bar, ensuring:
- Decrease in the energy bill for the pumps.
- Reduced risk of ruptures and leaks.
WaterTech’s ultrasonic water meters are full vacuum tube: having no bottlenecks, the sensors can work optimally with any flow rate. A feature that provides energy savings of up to a quarter compared to other meters. The other advantage is that because they can reduce pressure throughout the network, physical stress on pipes and joints is lowered, resulting in fewer ruptures, leaks, and consequent savings in maintenance costs.
The location of sensors in WaterTech’s ultrasonic water meters: an innovation that ensures their reliability over time
WaterTech has designed a novel horizontal position of the sensor pair that maintains measurement accuracy over time.
In fact, since the sensors are positioned at the centerline of the measuring tube, on a horizontal plane (and not at the bottom and on a vertical plane, as is the case in most cases), there are no obstacles to impurities (such as rust, solid particulates, sand) that may be present in the network and tend to settle on the bottom. By overheading it, the sensors always remain clean and ensure flawless operation even in the long run.
Robust design and quality materials: ultrasonic WaterTech meters withstand any environment
Water meters are often found in complex locations such as flooded manholes and below street level, subjected to harsh environmental conditions. WaterTech’s ultrasonic water meters are designed to meet installation even in very critical contexts. In fact, they are characterized by:
- robust and reinforced design: both the brass and composite bodies are particularly robust and able to withstand high mechanical stresses.
- fully submersible for the entire legal life (IP68 lifetime).
- durable connections that can also be connected to upstream and downstream non-straight sections (U0D0).
To ensure this performance, WaterTech relies on high-quality materials: from traditional cast iron and brass to thermoplastic composites with a high percentage of glass fiber and strongly reinforced with the use of ribs and veins throughout the measuring tube.
Dual circuits and dual batteries: WaterTech’s electronics ensure maximum accuracy, maximum durability and maximum reliability
Ultrasonic water meters have countless advantages and benefits in managing a water network. This, however, is only valid if the electronic meter works perfectly and the on-board electronics, i.e., the most delicate component, does not electrocute itself. This is a real risk, as smart water meters are often installed in critical environmental conditions, with high risk of being submerged for months and consequent danger of moisture infiltration inside them.
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A low-quality ultrasonic water meter, subject to the risk of malfunctioning or even not working at all, is far more damaging to the operator than an equally poor-performing mechanical meter. A failure of the electronics within an electronic meter with a single circuit means the total “death” of the meter and the loss to the distributor of the revenue associated with it. It is therefore critical that the static meter be able to last in the field for the full 13 years of its legal life!
WaterTech, thanks to its extensive experience in the field of gas smart metering, has introduced in the water field a solution never before seen in the market: the splitting of electronic components. WaterTech’s ultrasonic water meters are equipped with two electronic circuits, powered by two separate batteries.
One circuit and a dedicated battery are entirely dedicated to the metrology function; the other circuit, with its respective battery, is totally reserved for the transmission functionality. The two batteries are technologically very different and have distinctly different working methods and performance.
Piezometric sensors (i.e., the metrological function), in fact, need a stable and constant, but low-power supply. The associated battery is therefore required to release modest amounts of power but in a continuous manner. The communication modules that transmit data, while working at a much lower frequency, need significantly more power. The communication battery is therefore required to alternate long phases of “rest,” in which it is dormant, with very short phases of activity in which it must release large amounts of power.
Separating the circuits allows the two batteries to be optimized without compromise, leading to outstanding transmissive performance.
Thus, an ultrasonic static meter remains the best technology available on the market to optimize the water network. An indispensable interface that allows utilities to get the data they need to manage infrastructure in the most efficient way and go down the road to sustainability.
