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    Fluid Mechanics Presentation)

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    Azaz Ahmed
    This document discusses manometers, which are devices used to measure pressure using liquid columns. There are three main types of manometers: piezometer tubes, U-tube manometers, and inclined-tube manometers. Piezometer tubes are the simplest type and directly measure gauge pressure. U-tube manometers can measure pressures of both liquids and gases using two immiscible fluids. Inclined-tube manometers are used to more precisely measure small pressure changes by taking differential readings along an inclined tube. Manometers provide an important standard technique for pressure measurement across various applications.

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    Fluid Mechanics Presentation)

    Uploaded by

    Azaz Ahmed
    1K views18 pages
    This document discusses manometers, which are devices used to measure pressure using liquid columns. There are three main types of manometers: piezometer tubes, U-tube manometers, and inclined-tube manometers. Piezometer tubes are the simplest type and directly measure gauge pressure. U-tube manometers can measure pressures of both liquids and gases using two immiscible fluids. Inclined-tube manometers are used to more precisely measure small pressure changes by taking differential readings along an inclined tube. Manometers provide an important standard technique for pressure measurement across various applications.

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    A small 2 minute presentation on Manometers (FM).

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    This document discusses manometers, which are devices used to measure pressure using liquid columns. There are three main types of manometers: piezometer tubes, U-tube manometers, and inclined-tube manometers. Piezometer tubes are the simplest type and directly measure gauge pressure. U-tube manometers can measure pressures of both liquids and gases using two immiscible fluids. Inclined-tube manometers are used to more precisely measure small pressure changes by taking differential readings along an inclined tube. Manometers provide an important standard technique for pressure measurement across various applications.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPT, PDF, TXT or read online from Scribd
    Download as ppt, pdf, or txt
    1K views18 pages

    Fluid Mechanics Presentation)

    Uploaded by

    Azaz Ahmed
    This document discusses manometers, which are devices used to measure pressure using liquid columns. There are three main types of manometers: piezometer tubes, U-tube manometers, and inclined-tube manometers. Piezometer tubes are the simplest type and directly measure gauge pressure. U-tube manometers can measure pressures of both liquids and gases using two immiscible fluids. Inclined-tube manometers are used to more precisely measure small pressure changes by taking differential readings along an inclined tube. Manometers provide an important standard technique for pressure measurement across various applications.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPT, PDF, TXT or read online from Scribd
    Download as ppt, pdf, or txt
    of 18

    FLUID MECHANICS

    Manometers

    31st August, 2010.


    A study of the different types of
    manometers and the principleS
    on which they are based
    MANOMETRY

    It is A standard technique for measuring pressure


    that involves the use of liquid columns in vertical or
    inclined tubes.

    Pressure measuring devices based on this technique


    are called manometers.
    Definition of Pressure

    Pressure is defined as the amount of force exerted


    on a unit area of a substance.

    force N
    P  2  Pa
    area m
    Types of pressure:

    Absolute Pressure:
    Measured relative to a perfect vacuum

    Gage Pressure:
    Measured relative to the local atmospheric pressure
    Relationship between Absolute pressure
    and gage pressure:

    Absolute pressure = Atmospheric


    pressure + gage
    pressure
    Note:
    Absolute pressures are always positive.

    Gage pressure can be positive or negative, depending on


    whether the pressure is above atmospheric pressure (positive
    value) or below atmospheric pressure (negative value).

    A negative gage pressure is also referred to as a suction or


    vacuum pressure.
    Types of Manometers:

    1. Piezometer tube.

    2. U-Tube manometer.

    3. Inclined-Tube manometer.
    Piezometer Tube:
    The simplest manometer is a tube,
    open at the top, which is attached
    to the top of a vessel containing
    liquid at a pressure (higher than
    atmospheric) to be measured. An
    example can be seen in the figure .
    This simple device is known as a
    Piezometer tube. As the tube is
    open to the atmosphere the
    pressure measured is relative to
    atmospheric so is gauge pressure.
    Working:

    ra-ratm=gh

    Or for the gage pressure at


    A

    ra=gh

    Where g= specific gravity


    of material
    Although the piezometer tube is a very simple and
    accurate pressure measuring device, it has several
    disvantages.

    It is only suitable when the pressure in the container


    is greater than atmosphic pressure (otherwise air
    would be sucked into the system).
    U-Tube Manometer:
    Using a "U"-Tube enables the pressure
    of both liquids and gases to be
    measured with the same instrument. The
    "U" is connected as in the figure below
    and filled with a fluid called the
    manometric fluid. The fluid whose
    pressure is being measured should have
    a mass density less than that of the
    manometric fluid and the two fluids
    should not be able to mix readily - that
    is, they must be immiscible.
    Working:
    Pressure in a continuous static fluid is
    the same at any horizontal level so,
    Pressure at B= Pressure at C
    Pb=Pc

    From left hand arm:


    Pb=Pa+ρgh1

    From right arm:


    Pc=Patmospheric+ρmangh2

    Since we're measuring gage pressure, we can substract Patmospheric, giving


    Pb=Pc
    Pa=ρmangh2-ρgh1
    If the fluid being measured is a gas, the density will probably be very
    low in comparison to the density of the manometric fluid i.e. rman >>
    r. In this case the term ρgh1 can be neglected, and the gauge pressure
    give by:

    Pa=ρmangh2
    Inclined Tube Manometers:

    To measure small pressure changes, this type of


    manometers are used.
    One leg of the manometer is inclined at an angle,
    and the differential reading is measured along the
    inclined tube.
    Manometer used in steam engines
    A manometer with digital interface
    End of slideshow

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