What is a Flow Meter and how would I use one?

A flow meter (or flowmeter) is an instrument used to measure linear, nonlinear, volumetric, or mass flow rate of a liquid or a gas.

Why would I use a Flow Meter?

Many industrial applications require the measurement of liquid flow. An accurate flow measurement can make or break the profits and losses of some operations. Measurements that are inaccurate (or not taken at all) can lead to serious (or even disastrous) consequences in other cases. By measuring the liquid’s velocity or kinetic energy, most liquid flow measurement instruments determine the flow rate inferentially. A pipe or conduit’s velocity is determined by the differential pressure that is forcing the liquid through it.

Can Flow Meters be used Vertically?

Meter performance and accuracy are greatly affected by the orientation of the flow meter during installation. Most flow meters can be installed in any direction except the Rotameter, which can only be installed vertically with bottom-to-top flow.

What are the Types of Flow Meters?

There are many different types of flow meters but 4 main types you should be aware of.

  • Invasive devices – An invasive device has transducers that meet the flowing fluid. They are also called ‘wetted’ transducers. Flow profiles are distorted by intrusive devices, as shown in the top two diagrams. By introducing asymmetry to the velocity profile, the distortion often leads to mismeasurement.
  • Non-invasive – There will be no contact between the process flow and the sensor, as the sensor will be mounted externally.
  • Intrusive – The sensor is going to be placed/mounted in the pipeline, but it will either be in contact with the process flow, or it won’t be in contact with it at all.
  • Non- Intrusive – A sensor will be placed/mounted outside the pipeline, but it can be in-contact with the process flow, it can be in-contact with it or not in-contact with it.


Devices that are non-intrusive do not interfere with the flow profile in any way. This device has no pressure drop, resulting in a more cost-efficient operation. Moreover, they are non-invasive, which means they do not touch the fluid being measured.  Sensor heads can be damaged by dangerous or corrosive fluids, so this is very useful when measuring such fluids.  Additionally, it means that transducers can be used alongside heavily fouling fluids without being affected. In addition to saving money, this prolongs the life of the transducers

Our Flow Meters

Our Flow Meters are non-intrusive and non-invasive. Therefore, the installation of these meters does not require the pipeline to be broken into, so no damage to the pipeline is caused by doing so. As such, they are installed without any interruption to the process. This makes them ideal for use on several different lines for verification purposes as they are easily portable. There is no chance of leakage or contamination.  They can be installed in any direction and are easy to install as they simply clamp onto the pipe. Electrically conductive and non conductive liquids can be measured using ultrasonic flow meters. Designed to save you time and money, they feature no pressure loss or energy loss, a wide turn-down ratio with no need to stop the flow or cut the pipe, and minimal maintenance since the external transducers are not required to be cleaned periodically.


If you need to hire Flow Meters contacts us on 0330 9000 274 or contact our hire department at [email protected]