Yokogawa RAKD User Manual

V

Variable Area Flowmeter
Rotameter – The Original

• precise measurement of liquids and gases

• robust and universal

• proven device with an installed base of more

than 500,000 worldwide

• a wide product range

• many options and different materials

available

Proven technology:

Economical:
The Rotameter
(variable area) principle

The Rotameter is one of the oldest and

mature principles in flow measurement.

A float is guided inside a conically

shaped tube. The float rises within the

tube as the flow increases. This mechani-

cal principle is as simple as it is reliable.

Due to its operating principle the Rotameter

is usually installed in vertical pipes. Once the

process medium flows through the tube, the

gravimetric force, balances with the flow

resistive force in such a way that the position

of the float indicates the flow rate value.

Modular and flexible

Rotameter are completely modular

and flexible. The measuring tube

can be made of glass, plastic or

metal – depending on the application.

If the tube is made of metal the float

position is transferred to an outside indi-

cator via a magnetic coupling. In the case

of glass and plastic tubes you can simply

view the float position to get a reliable

reading of the flow rate.

The mechanical nature of the measuring

principle provides a flow device that does

not require any electrical power supply.

However, there are many applications in

process plants that do require electronic

indication and transmission of the measu-

red variable of flow to other associated

devices. This capability has considerably

expanded the range of applications for the

variable area flowmeter.