Water metering — BrandWiki

Types of metering technologies

There are two common approaches to flow measurement: displacement and velocity, each making use of a variety of technologies. Common displacement designs include oscillating piston and nutating disc meters. Velocity-based designs include single- and multi-jet meters and turbine meters.

There are also non-mechanical designs, for example, electromagnetic and ultrasonic meters, and meters designed for special uses. Most meters in a typical water distribution system are designed to measure cold potable water only. Specialty hot water meters are designed with materials that can withstand higher temperatures. Meters for reclaimed water have special lavender register covers to signify that the water should not be used for drinking.

Additionally, there are electromechanical meters, like prepaid water meters and automatic meter reading meters. The latter integrates an electronic measurement component and a LCD with a mechanical water meter. Mechanical water meters normally use a reed switch, hall or photoelectric coding register as the signal output. After processing by the microcontroller unit (MCU) in the electronic module, the data are transmitted to the LCD or output to an information management system.

Water meters are generally owned, read and maintained by a public water provider such as a city, rural water association or private water company. In some cases an owner of a mobile home park, apartment complex or commercial building may be billed by a utility based on the reading of one meter, with the costs shared among the tenants based on some sort of key (size of flat, number of inhabitants or by separately tracking the water consumption of each unit in what is called submetering).

Displacement water meters

Displacement meters are commonly referred to as Positive Displacement, or "PD" meters. Two common types are oscillating piston meters and nutating disk meters. Either method relies on the water to physically displace the moving measuring element in direct proportion to the amount of water that passes through the meter. The piston or disk moves a magnet that drives the register.

PD meters are generally very accurate at the low-to-moderate flow rates typical of residential and small commercial users and commonly range in size from 5/8" to 2". Because displacement meters require that all water flows through the meter to "push" the measuring element, they generally are not practical in large commercial applications requiring high flow rates or low-pressure loss. PD meters normally have a built-in strainer to protect the measuring element from rocks or other debris that could stop or break the measuring element. PD meters normally have bronze, brass or plastic bodies with internal measuring chambers made of moulded plastics and stainless steel.

Velocity water meters

A velocity-type meter measures the velocity of flow through a meter of known internal capacity. The speed of the flow can then be converted into a volume of flow to determine the usage. There are several types of meters that measure water flow velocity, including jet meters (single-jet and multi-jet), turbine meters, propeller meters and mag meters. Most velocity-based meters have an adjustment vane for calibrating the meter to the required accuracy.

Water meter index Display

Registers

There are several types of registers on water meters. A standard register normally has a dial similar to a clock, with gradations around the perimeter to indicate the measuring unit and the amount of water used, if less than the lowest digit in a display similar to the odometer wheels in a car, their sum is the total volume used. Modern registers are normally driven by a magnetic coupling between a magnet in the measuring chamber attached to the measuring element and another attached to the bottom of the register. Gears in the register convert the motion of the measuring element to the proper usage increment for display on the sweep hand and the odometer-style wheels. Many registers also have a leak detector. This is a small visible disk or hand that is geared closer to the rotation speed of the drive magnet, so that very small flows that would be visually undetectable on the regular sweep hand can be seen.

With Automatic Meter Reading, manufacturers have developed pulse or encoder registers to produce electronic output for radio transmitters, reading storage devices, and data logging devices. Pulse meters send a digital or analog electronic pulse to a recording device. Encoder registers have an electronic means permitting an external device to interrogate the register to obtain either the position of the wheels or a stored electronic reading. Frequent transmissions of consumption data can be used to give smart meter functionality.

LCD

There are also some specialized types of registers such as meters with an LCD instead of mechanical wheels, and registers to output data or pulses to a variety of recording and controller devices. For industrial applications, the output is often 4-20 mA analog for recording or controlling different flow rates in addition to totalization.

Water meter reading

Different size meters indicate different resolutions of the reading. One rotation of the sweep hand may be equivalent to 10 gallons or to 1,000 gallons (1 to 100 ft3, 0.1 to 10 m3). If one rotation of the hand represents 10 gallons, the meter has a 10-gallon sweep. Sometimes the last number(s) of the wheel display are non-rotating or printed on the dial face. The fixed zero number(s) are represented by the position of the rotating sweep hand. For example, if one rotation of the hand is 10 gallons, the sweep hand is on 7, and the wheel display shows 123456 plus a fixed zero, the actual total usage would be 1,234,567 gallons.

In the United States most utilities bill only to the nearest 100 or 1,000 gallons (10 to 100 ft3, 1 to 10 m3), and often only read the leftmost 4 or 5 numbers on the display wheels. Using the above example, they would read and bill 1,234, rounding to 1,234,000 gallons based on a 1,000-gallon billing resolution. The most common rounding for a particular size meter is often indicated by differently coloured number wheels, the ones ignored being black, and the ones used for billing being white.

Water meter smart metering technologies and usage

Smart metering technologies for water meters refer to advanced systems that enable real-time monitoring, data collection, and analysis of water usage through digital and connected devices. Unlike traditional mechanical water meters, smart meters are equipped with electronic components that measure water flow and transmit the data wirelessly to utilities and consumers. Key technologies include Automated Meter Reading (AMR), which provides one-way communication to collect usage data, and Advanced Metering Infrastructure (AMI), which supports two-way communication for enhanced features such as remote monitoring, leak detection, and dynamic billing. Smart water meters are integrated with Internet of Things (IoT) platforms, allowing for more efficient water management, reduced waste, and improved customer engagement.

RF Technologies and Protocols

Radio Frequency (RF) technologies form the backbone of smart metering systems by enabling wireless communication between meters and utility networks. Several RF technologies and protocols are widely used in smart water metering:

Wireless M-Bus (WMBus): WMBus, compliant with the European EN 13757 standard, is widely adopted across Europe for water, gas, and electricity metering.[12] It offers secure, reliable, and energy-efficient communication tailored for utility applications. The data collected by this mean are sent to the network using a WMUS Gateway (see below).
Wize technology: A protocol based on the 169 MHz frequency band, WIZE is designed for long-range, low-power communication. It is commonly used in Europe for water and gas metering due to its excellent signal penetration and scalability.[13]
LoRaWAN: LoRaWAN is valued for its long-range and low-power capabilities, making it suitable for large-scale deployments in both rural and urban settings. It is widely used in industrial and municipal applications.[12]
Zigbee: Known for its ability to create mesh networks, Zigbee is often used in urban environments where dense connectivity is required. It is energy-efficient and supports secure communication.[14]
NB-IoT and Cat-M: Narrowband Internet of Things (NB-IoT) and LTE Cat-M are cellular-based technologies that enable direct communication with cellular networks. These protocols are particularly suitable for large-scale deployments in areas with existing cellular infrastructure, offering extended battery life and robust coverage.[12]
Encoder receiver transmitter (ERT) technology is a widely used communication system in utility metering, particularly in the United States. Water meters are connected through a cable to an external unit called Meter Interface Unit (MIU) and gives the ability to transition between wired and wireless systems have made it a popular choice for utility providers seeking efficient and scalable metering solutions.[15]

Application-Layer Protocols in Smart Metering

Application-layer protocols operating above RF communication technologies to standardize data exchange, ensure interoperability, and enhance device functionality. These protocols enable integration of meters into broader utility and Internet of Things (IoT) ecosystems.

DLMS/COSEM (Device Language Message Specification/Companion Specification for Energy Metering) is one of the most widely adopted protocols in smart metering. It provides a flexible and standardized framework for data exchange between metering devices and utility systems. The protocol supports various communication technologies, including RF, wired, and cellular networks, and facilitates secure data transfer, structured data management, and remote monitoring.[16]

LwM2M (Lightweight Machine to Machine) is a protocol specifically designed for IoT devices, offering efficient resource management and secure communication over constrained networks. Its lightweight design makes it ideal for smart water meters and other low-power devices. LwM2M supports remote configuration, firmware updates, and real-time monitoring, enabling enhanced functionality and scalability in metering systems.[17]

Other application-layer protocols, such as MQTT (Message Queuing Telemetry Transport) and CoAP (Constrained Application Protocol), are also utilized in smart metering systems, particularly in IoT-centric deployments. These protocols focus on low-bandwidth, high-efficiency communication, ensuring reliable data exchange in diverse environments.

Smart Water Metering System: Infrastructure Overview

A smart water metering system integrates advanced water meters, communication networks, and centralized platforms like the Head-End System (HES) and Meter Data Management System (MDMS). Smart meters collect data on water usage, pressure, and anomalies, transmitting it through wireless networks. The HES aggregates and validates this data, forwarding it to the MDMS, which performs advanced analytics, trend reporting, and billing integration.

WMBUS Gateway for Water Meter Remote Reading

A WMBUS Gateway (Wireless M-Bus Gateway) is a communication device that enables remote reading of water meters by bridging the gap between the water meters equipped with Wireless M-Bus communication modules and centralized data collection systems. The gateway typically operates on standard frequencies such as 868 MHz (Europe) or other ISM bands.[20]

WMBUS gateways can be deployed as fixed gateways, installed at permanent locations to continuously collect data from meters within range, or as part of mobile solutions, such as drive-by or walk-by systems, where data is collected via handheld devices or vehicles equipped with receivers as they pass by the meters.

In some cases, electricity meters with integrated communication modules are also utilized as fixed gateways to collect data from nearby water and gas meters, leveraging their existing infrastructure to minimize deployment costs.

WMBUS Gateway for Water Meter Remote Reading

The collected data is then transmitted to a central server via technologies like GSM, GPRS, LTE, or Ethernet for analysis and management.

Applications and Benefits

The adoption of these RF technologies and protocols enables seamless integration of smart water meters into utility systems, offering several advantages:

Improved Efficiency: Automated data collection reduces manual labor and errors.
Enhanced Leak Detection: Real-time monitoring helps identify and address leaks promptly.
Dynamic Billing: Enables more accurate and flexible billing based on real-time usage.
Sustainability: Supports water conservation by providing detailed consumption insights.

Water meter standards and certification

Water meter Measurement standards and certification

Water meters are subject to measurement standards and certifications to ensure their accuracy, reliability, and compliance with regulatory requirements. The most widely recognized standards include the ISO 4064[30] series and the OIML R49 [31] standards, which define the performance, accuracy classes, and testing procedures for water meters.

In the European Union, compliance with the Measuring Instruments Directive (MID) is mandatory for water meters sold within member states, ensuring conformity with harmonized European standards.

In the United States, water meters typically adhere to the AWWA (American Water Works Association) C700 series standards, which specify design, materials, and performance criteria.

In Australia and New Zealand, water meters must comply with the AS 3565 standard.

Certification processes for water meters often include testing for

accuracy under varying flow rates,
durability under environmental stress,
and long-term stability.

Water meter potability standards and certification

Water meters used in potable water systems are required to meet stringent standards to ensure they do not contaminate the water supply or alter its quality. These standards address materials, coatings, and designs that come into contact with drinking water.

In the United States, compliance with NSF/ANSI 61 is mandatory, setting limits on leachable contaminants from water system components.

The European Union mandates conformity with the Regulation (EU) 305/2011 (Construction Products Regulation), alongside national certifications like

In Australia and New Zealand,[33] the AS/NZS 4020 standard governs the suitability of products for use with potable water, focusing on factors such as taste, color, and toxicity.

In Latin America, countries like Brazil and Mexico often reference international standards such as those from NSF International.

United Kingdom: WRAS Approval,
Germany: KTW Guideline,[32]
France: ACS Certification (Attestation de Conformité Sanitaire),

Ultrasonic meters

Ultrasonic water meters use one or more ultrasonic transducer to send ultrasonic sound waves through the fluid to determine the velocity of the water. Since the cross-sectional area of the meter body is a fixed and known value, when the velocity of water is detected, the volume of water passing through the meter can be calculated with very high accuracy. Because of water density changes with temperature, most ultrasonic water meters also measure the water temperature as a component of the volume calculation. There are 2 primary ultrasonic measurement technologies used in water metering:

Ultrasonic meters may either be of flow-through or "clamp-on" design. Flow-through designs are those where the water passes directly through the meter, and are typically found in residential or commercial applications. Clamp-on designs are generally used for larger diameters where the sensors are mounted to the exterior of pipes, etc.

Ultrasonic water meters are highly accurate devices, with residential models capable of measuring flow rates as low as 1 liter per hour (L/h).[2] They feature wide flow measurement ranges, require minimal maintenance, and have long lifespans due to the absence of internal mechanical components that could wear out over time.[3] This design ensures stable long-term operation and reduces the need for maintenance.

Although relatively new to some markets, including the American water utility sector, ultrasonic water meters have been well-established in Europe, Asia, and other regions. Their growing popularity is driven by the increasing demand for reliable, low-maintenance, and durable metering solutions suitable for diverse climates and water supply conditions.[3] Furthermore, the integration of smart meter technology with ultrasonic systems is accelerating their adoption worldwide, as utility providers seek more efficient and accurate data collection methods.

Doppler effect meters which utilize the Doppler Effect to determine the velocity of water passing through the meter.
Transit Time meters which measure the amount of time required for the ultrasonic signal to pass between 2 or more fixed points inside the meter.

Ultrasonic meters

Doppler effect meters which utilize the Doppler Effect to determine the velocity of water passing through the meter.
Transit Time meters which measure the amount of time required for the ultrasonic signal to pass between 2 or more fixed points inside the meter.

Types of metering technologies

Displacement water meters

Velocity water meters

Water Meter Length and Diameter

Diameter

Length

Water meter index Display

Registers

LCD

Water meter reading

Water meter smart metering technologies and usage

RF Technologies and Protocols

Application-Layer Protocols in Smart Metering

Smart Water Metering System: Infrastructure Overview

WMBUS Gateway for Water Meter Remote Reading

WMBUS Gateway for Water Meter Remote Reading

Applications and Benefits

Prevalence

Benefits

Costs

Problems

Water meter standards and certification

Water meter Measurement standards and certification

Water meter potability standards and certification

Environmental constraints

Innovation in water metering

Additional sensor

Data analytics

Leak Detection

Effect on consumption

Calibration and verification bench

Prepaid and Postpaid water meters

Main suppliers

See also

Further reading

External links

References

Multi-jet meters

Turbine meters

Compound meters

Electromagnetic meters

Ultrasonic meters

Coriolis Water Meter

Multi-jet meters

Turbine meters

Compound meters

Electromagnetic meters

Ultrasonic meters

Coriolis Water Meter