A water meter is a device used to measure the volume of water passing through any particular part, like a pipe or tap, in gallons, CCF (Centum Cubic Feet), or cubic meters.

In a country like India, where water demand is very high and 49 billion liters of water are wasted every day, water meters play an important role in smart water management by measuring, reducing, and controlling water consumption. 

These meters help detect water leaks, monitor water consumption, and conserve water. They can reduce costs, provide accurate billing, and provide easy maintenance. 

Equipped with advanced technology, these meters provide higher energy efficiency, whether used in commercial, industrial, or residential locations.

Here, we have listed the types of water meters, their working ideology, and their uses. It might help you choose the right water meter according to your needs.

Difference Between A Water Meter And A Water Flow Meter

Read More About: Water Flow Meters: How They Work And Different Types

Types Of Water Meters

Several types of water meters are used for commercial, residential, and industrial applications. Some types are explained here.

1. Positive Displacement Meters

Positive displacement meters, or “PD meters,” measure the volume of water. PD meters can measure the flow of liquids with an accuracy range of 0.1% to 2.5%.

These meters have a built-in strainer that keeps away any waste elements from damaging any internal parts of the water meter. They are generally sized between 5/8″ and 2″. 

They only sense the volume of water and are very sensitive to water impurities. Due to the many moving parts in them, they need a lot of maintenance and replacement.

2. Velocity Meters

Velocity meters measure the velocity of water. The working principle of velocity meters is, “The amount of water flowing is closely connected to its speed; i.e., the flow speed is converted into the volume of flow to determine the water consumption.” 

It gives good precision if it is connected to a calibration device. It can function with water impurities. There are several types of water velocity meters, such as—

(A) Multi-Jet Meters

Multi-jet meters are named for their use of many jets of water to measure the flow rate. Based on a time-tested principle, they are accurate at low flow rates. 

The general sizes of these meters are between 5/8” and 2”. In these meters, there is a chamber surrounded by several ports that make many jets of water against a turbine. This type of water meter is also best for commercial and residential use.

(B) Single-Jet meters

A single-jet meter uses one stream of water. They are based on the ‘Velocity Principle.’ The general size of these water meters is between 5/8” and 3/4″. 

The water in these meters is directed to the impeller through a single nozzle. As the water flows, it makes the impeller spin, which is directly related to the amount of water flowing. They are best for residential and small industrial applications.

(C) Turbine Water Meters

In this device, the turbine is placed in the center of the flow path with angled blades that spin as water flows through. A magnet in the turbine creates a pulse each time it passes a sensor. 

Counting the pulses helps calculate the flow rate and total volume. This provides a highly precise measurement. 

It is used for large pipe diameters and is ideal for lower flow rates with high volume (size 1.5” to 3.0”). They are useful for large commercial spaces and fire protection.

(D) Compound Water Meters

Compound water meters are used when there is a need to measure both high and low flow rates. It is a combined form of a PD meter (low flow rate side) and a turbine meter (high flow rate side). 

When the flow rate of liquid is high, the turbine meter measures the rate. At the low flow rate, the PD meter measures the rate. When we need to check values, the readings from both sides are added. Compound water meters are used in hospitals and large industries.

3. Electromagnetic Water Meters

The working principle of electromagnetic water meters is based on Faraday’s Law to measure liquid velocity. These meters are also known as mag meters. 

These meters use sensors and transmitters to measure water flow, enhancing their accuracy. They are commonly used in commercial and industrial buildings.

4. Ultrasonic Water Meters

An ultrasonic water meter uses ultrasonic sound waves through the fluid to detect the velocity of the water. If the cross-sectional area of an outlet is fixed, the velocity of the water can be calculated with high accuracy.

Due to changes in the density of water with temperature, it also measures the temperature and volume. Ultrasonic water meters are also of two types: these are

(A) Transit-Style Ultrasonic Meter

Transit-style ultrasonic meters (suitable for clean liquid) use two transducers (ultrasonic wave sensors). They measure the velocity of water based on the time difference in flow between the two transducers as water flows through the pipe.

These meters can be highly useful for commercial and industrial applications. They are very easy to install and relatively inexpensive.

(B) Doppler-Style Ultrasonic Meter

Doppler-style ultrasonic meters are based on the ‘Doppler effect’ (suitable for dirty liquids). They detect the bubbles or solid particles present in the water and then use the frequency shift of these bubbles or particles to measure the velocity of the water. They can be highly useful for industries.

5. Prepaid Water Meters

Prepaid water meters provide water after paying bills for water, like electricity bills. The properties of prepaid water meters include time monitoring capabilities, water conservation awareness, and the ability to share data through direct contact or low-frequency communication, making it easier to access and manage. They can be helpful for residential and commercial applications.

Factors To Consider When Choosing A Water Meter

There are many factors to consider when choosing the best water meter for your residential, commercial, and industrial needs. Some factors are covered here to help you choose the right water meter. These factors are:

Flow Rate

The meter should be appropriately sized for the flow you need, ensuring accurate measurement. Larger meters may not be as precise at lower flow levels, which could affect efficiency.

Flow Profile

It is very important to know about the flow profile of the water meter because the flow profile of a water meter ensures it measures water accurately at all levels of usage, from small to large amounts. This helps to track consumption fairly and promote the efficient use of water resources for everyone.

Temperature And Pressure

The important factors in choosing a water meter are temperature and pressure because temperature affects water viscosity. At higher temperatures, the viscosity of water decreases, allowing it to flow more easily through pipes, which may cause the meter to be unable to record the data accurately. Additionally, pressure can affect the hydraulic performance and velocity profiles.

Accuracy

Accuracy is also an important factor in choosing a water meter. Higher-accuracy water meters can help consumers with precise measurement, correct billing, identifying leaks, and improving flow management. Before selecting a water meter, consumers need to check all requirements.

Installation Parameters

Proper installation is crucial for ensuring that the water meter functions efficiently. During the installation process, factors such as pipe configuration, flow direction, and a straight pipe must be carefully considered, as they can impact accuracy. Be sure to select meters that meet these important requirements.

Pricing

Pricing is a general factor to consider when purchasing anything. But in the case of a water meter, it is not only the cost of the meter that matters; upkeep, data recording, and calibration also need to be considered when buying.

Technological Advancements In Water Meters

Advancements in water meters are much needed now and in the future because the meters need to be updated to improve accuracy, billing, and maintenance.

Nowadays, smart water meters use real-time data with advanced technology and water quality sensors. This helps detect water leaks, providing better accuracy in billing and making repairs and maintenance easier. 

Choosing the right water meter tailored to specific needs is equally important to get these benefits. Factors like meter size, water source and cleanliness, pressure loss, budget requirements, and more need to be considered for optimal performance. 

If you have further doubts or need guidance, you can always contact your plumber for expert advice!