Classification of Flowmeters

Flowmeters can be divided into two types:

·        New-technology flowmeters

·        Traditional-technology flowmeters

This article states the distinction between new-technology and traditional technology flowmeters.  A table at the end shows the classification between the two types.

New-Technology Flowmeters

New-technology flowmeters use technologies that have been introduced more recently than traditional technologies such as differential pressure flow.  Most new-technology flowmeters came into industrial use in the 1960s and 1970s, while differential pressure flowmeters were used in the early 1900s.  Each new-technology flowmeter is based on a different physical principle, and constitutes a unique approach to flow measurement.

New-technology flowmeters have the following characteristics:

1. They have been introduced since 1950.

2. They incorporate technological advances that avoid some problems inherent in earlier flowmeters.

3. They are more the focus of new product development by the major flowmeter suppliers than traditional-technology meters.

4. Their performance, including criteria such as accuracy, is at a higher level than the performance of traditional-technology meters.

Flowmeters that incorporate newer technologies are here as “new technology” flowmeters.  Included in this category are Coriolis, magnetic, ultrasonic, vortex, and multivariable differential pressure (DP) meters.  All these flowmeters have been introduced since 1950.  Magnetic flowmeters first came onto the market in 1952, while Tokimec (then Tokyo Keiki) introduced ultrasonic meters in Japan in 1963.  Eastech brought out vortex meters in 1969, and Yokogawa developed its vortex meter at about the same time.  Micro Motion introduced Coriolis flowmeters in 1977.  Bristol Babcock brought multivariable DP flowmeters onto the market in 1992.

Traditional Technology Flowmeters

Despite the growth of new-technology flowmeters such as Coriolis and ultrasonic over the past few years, traditional technology flowmeters are holding their own.  Many users are still selecting differential pressure (DP), turbine, positive displacement, and other more traditional meters as their flowmeter solutions.  This article describes the traditional technology flowmeter market, and explains why this market is still holding onto market share even in the face of competing technologies.

Traditional technology flowmeters share the following characteristics:

  1. They were introduced before 1950.
  2. They are less the focus of product development than new-technology flowmeters
  3. Their accuracy level is not as high as that of new-technology flowmeters.
  4. They are slow to incorporate recent advances in communication protocols, such as HART, Foundation Fieldbus, and Profibus.

Traditional technology flowmeters include DP, positive displacement, turbine, open channel, and variable area.  Business is brisk with many of these meters.  In terms of units, there were more positive displacement and also more turbine flowmeters sold worldwide in 2001 than all the new-technology flowmeters combined (see chart).  Why are customers still so loyal to these meters?

Flowmeters that incorporate more traditional technologies are traditional technology flowmeters.  These include single variable DP, positive displacement, turbine, open channel, thermal, and variable area flowmeters.  As a group, these flowmeters have been in use longer than new-technology meters.  Generally speaking, they have higher maintenance requirements than new-technology flowmeters.  And even though suppliers continue to introduce new traditional-technology flowmeters, these meters are not so much the focus of new product development than new-technology meters. 

The history of turbine flowmeters goes back to the mid-1800s, while DP meters came into use in the early 1900s.  Many of the problems inherent in DP flow measurement have to do with the primary elements used together with a DP transmitter.  For example, orifice plates can be knocked out of position by impurities in the flowstream, and they are subject to wear.  Positive displacement and turbine meters have moving parts that are subject to wear.  The accuracy levels of open channel, thermal, and variable area flowmeters are substantially lower than that of new-technology flowmeters.

New Technology and Traditional Technology Flowmeters

New Technology Flowmeters

Traditional Technology Flowmeters


Differential Pressure (DP)


Positive Displacement





Open Channel

Multivariable Differential Pressure (DP)

Variable Area




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