From Flow Measurement
Variable area flowmeters were invented in the nineteenth century but were not
introduced for general industrial use until the 1930s. They became very popular
and widely used since they offered a low-cost alternative to the differential pressure
flowmeter—especially in smaller pipe sizes.
The original designs introduced were available for visual indication of flow rate
only. In the 1940s designs became available with secondary functions such as
transmission, alarm, recording, and totalizing. Variable area flowmeters are available
in pipe sizes from 1/8 inch (0.3 cm) to 8 inches (20 cm) and full scale flow
rates from less than one ml/minute to over 1000 gpm (3800 lpm) of water and
approximately 30 scc/minute to 2500 scfm (71 nm3/min) of air.
Since they are in-line devices, they have been designed for a wide range of line
pressure ratings, pipe connection types, and many different materials of construction.
Products & Services
Topics of Interest
Most flow measurements are made by meters that are installed in-line such that all of the fluid passes through the meter body. Insertion (sampling) flow measurement is a different technique because...
Next time you want to measure flow, think of the rotameter first. This simple and economical means of flow control, with local readout, for a wide variety of gases and liquids of low-to-moderate...
With the many flowmeters available today, choosing the most appropriate one for a given application can be difficult. This article discusses six popular flowmeter technologies, in terms of the major...
A large number of many types of flowmeters are available today. The most commonly used is the variable differential pressure type, which includes “the orifice meter,” an engineering...
The selection of six types of flowmeters was previously discussed here (previous article, pp 176- 182, in this book). These were: variable-area, mass, Coriolis, differential-pressure, turbine, and...