How Does A Variable Area Flow Meter Work

Is example of variable area flow meter?

Rotameters. The simplest example of a variable-area flowmeter is the rotameter, which uses a solid object (called a plummet or float) as a flow indicator, suspended in the midst of a tapered tube: As fluid flows upward through the tube, a pressure differential develops across the plummet.

What is the main drawback of variable head flow meter?

Limitations: Square root relationship between flow rate and differential pressure, therefore smaller span. Affected by pressure and density changes.

What are the advantages of using a variable area flowmeter?

Advantages: The major advantage of the variable-area flowmeter is its relative low cost and ease of installation. Because of its simplicity of design, the variable-area meter is virtually maintenance-free and, hence, tends to have a long operating life.

Which one of the following is a variable area flow meter?

Rotameters are the most widely used type of variable-area (VA) flowmeter. In these devices, the falling and rising action of a float in a tapered tube provides a measure of flow rate .

What is a variable area meter?

Variable Area flow meters measure volumetric flow of liquids and gases. This technology is based on the variable area principle, where flow raises a float in a tube, increasing the area for passage of the fluid through the meter.

What is a variable area meter used for?

The variable area flow meter is an industrial flow meter used to measure the flowrate of liquids and gases. The variable area meter consists of a tube and float.

Why are flow meters called variable head meters?

The basic principle on which variable-head meters are based is that when a fluid stream is restricted, its pressure decreases by an amount that is dependent on the rate of flow through the restriction. Therefore, the pressure difference between points before and after the restriction can be used to indicate flow rate.

Why variable area flowmeter consists of a tapered glass tube?

Working principle:

The fluid flows up through the tapered tube forcing the float to a position with sufficient free area to enable the flow to pass. This free area is related to the flow rate, the weight of the float and the density and viscosity of the fluid.

Which principle is used in variable head flow meter?

Variable area flowmeters are very simple yet versatile flow measurement devices for use on all types of liquids, gases and steam. They operate on the variable area principle, whereby a flowing fluid changes the position of a float, piston, or vane to open a larger area for the passage of the fluid.

Which of the following flow measuring device does not cause of obstruction of flow?

Explanation: Orifice plate, venture tube and flow nozzle all these devices are used for flow obstruction. Sphere can't be used for flow obstruction. Explanation: An orifice plate is a device used for measuring flow rate, for reducing pressure or for restricting flow. It is also used to make temporary flow measurements.