How much is a flow meter? Well, how long is a piece of string?
Indeed, before a question like that makes any sense at all, we’ll need to remind ourselves about
this ingenious, incredibly diverse but increasingly accessible technology category that just about
any business or organisation can now afford.
In a nutshell, a flow meter is any device that measures the flow of liquids or gases – whether it’s
needed for monitoring, control or something else. From the water flowing down a river to gas in a
pipe, there are a million potential applications for the various flow meter types on the market. In
every category, though, rapid technological evolution means that flow meters of every type are
constantly becoming more precise, more accurate and more diverse in the flow measurements and
Let’s take a bird’s eye view of what the latest flow meters may set you back:
1. Turbine-based water flow meter
Trying to price ‘a water flow meter’ is a little like trying to price ‘a car’ – but what’s for sure is that you
can certainly get one on your hands for pocket change. The most rudimentary water flow meter fits
onto a pipe, with a free-running turbine in a chamber simply measuring how much liquid is flowing
through the proportionately-rotating turbine.
Used in: washing machines, dishwashers, beverage dispensers.
Price: Less than $100
2. Oval gear flow meter
While water flow meters like the one mentioned above are suitable for simple, water-like liquids,
you’ll need something more expensive if you want to accurately measure a more complex liquid
such as oil or fuel. This type of flow meter also fits on a pipe, but it works not with a turbine but with
two oval-shaped gears that are turned around by the flow of the fluid.
Used in: Engines & hydraulics.
Price: Less than $700
3. Gas flow meter
While the two flow meter types described above measure liquids, there’s also an impressive range
of flow meters on the market that are designed specifically for gases like argon, CO2 and helium –
and they are typically more expensive again. As well as flow, sophisticated gas flow meters will
normally measure temperature and pressure as well – and need features built in that ensure that
any of the pressure in the system does not leak.
Used in: Manufacturing, chemical process industries.
Price: Around $1500 and up
4. Air flow meter
Finally, let’s take a look at a sophisticated air flow meter, which is used to detect and analyse the
presence and movement of air – for instance to calculate a precise air-fuel ratio for combustion. It
works on the principle of two sensing wires, one of which is heated by an electrical current, with
that temperature then compared with the non-cooled wire with the current proportionately adjusted.
Now, while air flow meters of rudimentary types can be bought for a triple-digit price, there are
devices on the market that – according to the manufacturer – are “so precise that even the flap of a
butterfly’s wings will not be missed”.
Used in: Engines, pharmaceutical manufacturing, mining & nuclear environments
Price: As much as $15,000+
So, just like trying to price ‘a car’ or measure ‘a piece of string’, it’s easy to see that flow meters will
set you back anything between pocket change and the price of a round-the-world trip! The key, of
course, is not just zeroing in on the flow meter technology category you require, but matching it with
the level of precision, reliability, performance and features for your specific application – whatever it
happens to be. As always, and especially when your organisation’s crucial operations or
compliance are at stake, ensure that experienced and credentialed experts are always guiding your