Learning More about Liquid and Gas Measuring Instrument Flow Meters

by Hemant Sharma Digital Marketing Manager

A flow meter is an instrument usually used to measure nonlinear, linear, volumetric or mass flow rate of gas or liquid. When selecting flow meters, one should take into consideration such insubstantial factors as expertise of plant personnel, their experience with maintenance and calibration, spare parts accessibility, and mean time among failure history, etc., at the specific plant site. Volumetric flow meters measure the fluid volume passing through it.  

Flow Meters Uses

Precision flow meters are used to offer precise monitoring and or flow control. Certain industrial applications necessitate precise calculation of quantity, for instance precision servo-valve development for the aerospace industry. In contrast, an application to gauge water flow to a vineyard may only need a measurement accuracy of 5% to 10%.

There are no specific flow meters which are appropriate for all applications. Choosing the right flow meter is necessary in order to accomplish your purpose of measurement.  Each type of low meter has its own specifications and features. The cost of the liquid, gas and vapour measuring flow meters depends on its features, specifications, and offcourse brand. There are typically trade-offs with each meter type, thus knowing the vital specifications will be vital.

What are the varied types of flow meters?

There are a diverse range of the flow meters. Choose one considering your industrial usage. Some of the most common flow meters are:

  • Ultrasonic Flow Meters
  • Turbine Flow Meters
  • Rotameters or Variable Area Flow Meter
  • Spring and Piston Flow Meters
  • Positive Displacement Flow Meters
  • Vortex Meters
  • Mass Gas Flow Meters
  • Paddlewheel Sensors

Working of flow meters

Flow meters are generally used to measure mass or volume. Its working is related to measuring the amount of steam flowing, liquid or gas through or around the sensors of flow meters.  

Things to consider when choosing Flow Meters  

At the time of looking for flow metres online, it is important to consider a few things which are as listed below:

  • Maximum and minimum flow rates
  • What is the Liquid or Gas being measured?
  • The fluid viscosity and temperature
  • What are the accuracy requirements?
  • The maximum pressure at the location.
  • Fluid compatibility with the materials of construction
  • What kind of output signal or readout do you require?
  • Is the meter mounted in a dangerous location where volatile gas may be nearby?
  • What pressure drop is permissible?
  • Is the fluid flow intermittent or continuous?

Correct Installation of Flow Meters

In order to derive the required accuracy when it comes to measurement it is essential to ensure the correct installation of a flow meter. For example - in liquid service, ensure that the flowmeter is set-up in such a way that it remains filled with liquid, as vapor / gas in the flowmeter can change its geometry and unfavourably affect correctness. In gas/vapor service, ensures that the flow meter is set-up in such a way that the flow meter stays full of vapor / gas, as liquid in the flowmeter can modify its geometry and affect accuracy adversely.

Issues located upstream of the flowmeter, for instance pipe elbows and control valves, can affect measurement accuracy adversely, as the flowmeter may not be able to measure disturbed flow streams precisely. Also, ensure to design the upstream and downstream appropriately piping with adequate straight run to get rid of disturbances that can affect measurement accurateness.

Be particularly cautious when flow is two-phase, such as gas / liquid flow and liquid/solid flow, as these flows can affect the accuracy of many flowmeters unfavourably. Also, be cautious as some flow meters can become plugged and stop working in solid / liquid flow streams.


Each category of flowmeter has its own installation constraints and specific applications. There is no "one size fits all" flowmeter. The way to choose the right flowmeter is to use the application as your guide, not the technology.

Most of these technologies will work well on numerous applications. If you start with the application, you can choose the technology you wish to use based on cost, accuracy, reliability and durability, instead of making the technology you select the application you have.

If you are looking to buy flow meters online you can visit online platforms namely Bellstone Online and more for better deals!

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About Hemant Sharma Advanced   Digital Marketing Manager

74 connections, 0 recommendations, 174 honor points.
Joined APSense since, January 10th, 2019, From Delhi, India.

Created on Aug 6th 2019 07:07. Viewed 181 times.


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