The two most popular varieties of water meters are single jet water meter En multijet watermeter. To assist you in making a better decision for your project, this article will thoroughly compare these two kinds of water meters from a variety of angles, including design, performance, and relevant scenarios.
1. Design and Operation
The two operate on the same basic principle, which is the measurement of flow velocity: the water flow is determined by the rotation speed produced by the water flow’s impact on the impeller, which allows for the measurement of water consumption. Nonetheless, the two have quite different designs:
The single jet water meter introduces water into the metering chamber through a single inlet. The water impacts the impeller to rotate, thereby driving the counter to record the water consumption. This design is simple and low-cost, but the impact of the water on the impeller is unidirectional, which may cause the impeller bearing to wear faster, affecting the measurement accuracy and life.
The multi-jet water meter uses multiple (4-6) nozzles to disperse the water flow into multiple strands, impacting the impeller from different angles, so that the impeller is more evenly stressed and reduces the wear on a single impeller. And the smoother rotational motion produced by this design can effectively improve the detection of low flows, this means multi-jet meters maintain accuracy even at very low flows. However, the added nozzles and flow guides make multi-jet meters more complex to build than single-jet designs.
| Features | single jet water meter | multijet watermeter |
| Number of entrances | 1 | Multiple, usually 4-6 |
| Impeller force mode | Single point force | Multiple points of force |
| Structural complexity | Simple | Complex |
2. Accuracy and reliability
Multi jet water meters have higher measurement accuracy and better anti-interference ability because the water flow hits the impeller from multiple directions and the force is more uniform. They can measure low and high flows more accurately and are suitable for complex or changing water use environments.
Some old single jet water meters have relatively low measurement accuracy, especially under low or high flow conditions, which are easily affected by factors such as water flow fluctuations and impurity deposition, resulting in measurement errors. In addition, due to its structural characteristics, it is more likely to reduce accuracy due to wear and tear during long-term use.
With the maturity of technology, the accuracy of many single jet water meters is comparable to that of multi jet water meters, and they are fully capable of most water use environments. For example, BMAG’s multi jet and single jet water meters can both achieve a high accuracy of R200.
| Performance indicators | single jet water meter | multijet watermeter |
| Nauwkeurigheid | ±2% in a wide flow range | ±2% can be achieved even closer to the start flow |
| Transformation ratio | 1:80–1:200 | 1:80–1:200 |
| Pressure loss (at maximum flow) | 0.2–0.3 bar The water flow path is relatively concentrated, which will cause greater pressure loss under high flow conditions | < 0.2 bar Multiple nozzles disperse the water flow, reducing the concentrated impact of the water flow, thereby reducing pressure loss |
| Particle tolerance | Generally, fine filtration is required | Better, low wear rate |
3. Cost and Installation
Single jet water meter is simple in design, low in manufacturing cost, and easy to install and maintain. Its price is generally lower than that of multi jet water meter, and the wholesale price of household type is between $7 and 30. However, single jet water meter is more sensitive to installation location and water flow conditions, and usually needs to be installed horizontally to ensure optimal performance.
Multi jet water meter is more complex in structure, high in manufacturing cost, and relatively complex in installation and maintenance. Therefore, its price is usually higher than that of single jet water meter, and the wholesale price of household type is between $10 and 100. However, multi jet water meter is more adaptable to installation location and water flow conditions, and can maintain high measurement accuracy in water flow in different directions. Some models of multi jet water meter can be installed vertically, with higher installation flexibility.
Please note: Single jet types are usually 20–30% cheaper than comparable multi-jet types, but low price does not mean high cost performance. Over time, the higher upfront cost of a multi-jet meter may be offset by more stable accuracy in challenging conditions.
4. Applicable scenarios
Single jet water meter is suitable for residential and small commercial buildings, especially those projects with relatively stable water consumption, not particularly strict requirements for accuracy, and greater cost constraints. It is the first choice for many families and small businesses.
Multi jet water meter is more suitable for large residential, commercial and industrial applications, such as multi-family houses, office buildings or industrial facilities, where water consumption fluctuates greatly and requires high-precision measurement. In addition, they also show better tolerance when dealing with water flows containing impurities.
5. Maintenance and life
Both can have a service life of 15-20 years or more, but the life of a multi jet water meter is usually longer than that of a single jet water meter.
Single jet water meter has low maintenance requirements due to its simple structure, but the wear of the impeller bearing may lead to a shortened life. In addition, impurities and sediments can easily affect its measurement accuracy.
Multi jet water meter has a longer service life due to more balanced force and less wear. At the same time, their multi-stage filtration system can reduce the impact of impurities on measurement and improve reliability.
6.Intelligent Capabilities
Both can support communication protocols such as M-Bus, LoRaWAN™, NB-IoT, and realize intelligent functions such as remote reading through external or built-in integrated modules.
