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A Selection Guide for Digital Water Flow Meter

Unfortunately, over 75% of installed flow meters around the world are not functioning as expected. 90% of these claims result from poor selection of digital flow meters. Proper selection and installation of flow meters need to be done by an expert with years of experience and skills. Knowing what each type of liquid flow meter is supposed to do is the most important requirement. In addition, repeatability and accuracy are major concerns when it comes to measuring control processes. 

When selecting a digital water flow meter, there are several questions that you need to ask yourself. Among them is whether a remote or a local indication is needed. If a remote signal is needed, the plant manager needs to understand whether its purpose is to start or stop another device or act as a proportional signal. It is also advisable to know whether the fluid is electrically conductive or not. This is especially useful if you intend to use electromagnetic flow meters since they can’t work with fluids that are not electronically charged. 

An Overview

Other factors that need to be considered are the fluid characteristics that the liquid flow meter is going to measure or monitor. This includes the temperature, the pressure, the density, the viscosity, the surliness, and how clean the fluid is. The piping requirements of the digital water flow meter are also an important aspect to note when selecting a flow meter. When you are about to make the final choice, it is critical to know what the flow meter can or cannot do. 

All flow meters have their pros and cons regardless of the application they will be used on. How well an instrument can work, plus its shortcomings, should be weighed against the application requirements to know whether it is worth it. Unfortunately, many users buy flow meters hoping that they will function as required, only to find out the manufacturer had other ideas in mind. 

It is advisable to seek reputable liquid flow meter providers when you want to buy one. The reason being that they offer reliable products and services. Above that, they will also help you pick the right measuring instrument by providing checklists, questionnaires, and specification sheets. These guides have critical information that enables the users to secure proper flow meters designed for the right job. 

New Enhanced Flow Measurement Technologies 

In recent years, many improvements and innovations have occurred, targeting particular applications. While this is aimed to improve the efficiency of flow meters, it makes it harder for users to make the right choice. For example, there are advanced metering technologies with computer programs to help operators calculate tedious calculations. They have simplified calculations that used to take hours. Computer programs can now do these calculations in seconds.

An Overview of Factors to Consider When Selecting a Digital Water Flow Meter 

Buying proper flow meters will help you achieve the company’s bottom line and prevent losses that come from inaccurate flow measurement and high maintenance costs. Below is an overview of considerations that will guide you through the flowmeter selection process. 

Flow Meter Cost 

Flow meters are available at a wide range of prices. Mass flow meters are the most expensive categories of flow meters, the lowest costing about $3500. The cheapest flow meter categories are variable area flow meters, with smaller units going for less than $100. While it is important to look at the cost of particular flow meter devices, it is also advisable to look at the system’s total cost. A good example to explain this factor is the orifice flow meter that costs about $50. This may sound very cheap, but remember that you will have to include the transmitter for about $500 to $600. The cost escalates further when you include installation and sensing line fabrication costs. 

Learn About Process

Before specifying the counter, it is important to fully understand the entire process and its location. During the design process, plant operators participate in discussions about maintenance, calibration, and visits. Do I need to add a stream? Transfer to SCADA system (supervisory control and data acquisition) or available on the Internet? The starting point is to determine who will use the meter and how to use it.


Once in a while, all flow meters will require initial calibration to ensure that measurement accuracy is maintained. In most cases, the manufacturers are the ones who will provide this essential service. By doing this, they cater to specified service conditions. However, sometimes the plant may have its experts who can perform the calibration process, which is also well-provided they reset the flow meters to standardized parameters. Flowmeter calibration needs depend largely on how well the meter matches the application.

Some fluids that flow through flow meters may have corrosive, erosive, or abrasive characteristics. Within a few months or years, you will find out that some components of the flow meters will start wearing out, affecting the reading accuracy. The susceptibility of different flow meters varies. An example is the turbine flow meter, where wearing out of individual blades tends to affect the flow meter’s performance. 

If the application demands high accuracy levels, it is important to frequently check and calibrate the flow meter. Other flow meters can run for years without calibration because nothing hardly changes in such flow meters’ performance or the application is non-critical. 

Special equipment may be required to perform the calibration process on some flow meters. As a user, you may need to take the liquid flow meter to the manufacturer for calibration since the calibration instrument is available there. The manufacturer can also decide to take the calibration instrument to the user’s plant for on-site calibration. 


Several factors influence the lifespan and maintenance needs of flow meters. One of the most important of these factors is using the right flow meter with the right application. If the instrument is not paired with the right application, it will start causing issues early. The type of flow meters that don’t require much attention are those that don’t have moving parts. However, this doesn’t mean that they won’t need any maintenance. 

Differential pressure flow meters require much attention since they need extensive piping, valves, and fittings. All these are necessary while connecting to their secondary elements. This means that they will require regular maintenance after a short while of service. Impulse lines have to be cleaned or replaced regularly since they can corrode or plug. If placed wrongly, the secondary elements may cause issues such as measurement errors. Moving and setting up secondary elements may be expensive. 

Periodic inspection of internal parts flow meters with moving parts is necessary, especially if the measured media is viscous or dirty. Filters are needed in these meters to prevent wearing and fouling. In addition, inflow meters such as the electromagnetic or ultrasonic flow meters that don’t contact the measured fluids and have moving parts may develop issues with electronic components in their secondary elements. 


Proper selection of digital water flow meter devices is paramount if you want to maximize their potential. Failure to select, install, use, and maintain the correctly may lead to frequent breakages, inaccurate flow readings, and losses. While selecting proper flow meters is critical, buying flow meters from reputable suppliers is equally important; therefore, do your research first before settling for a particular vendor. 

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