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CHAPTER 6 (15-32), NAIF SHAHMI BIN SUKHAIMI(2018679698) - Coggle Diagram

- - - - The sound waves are directed to the free surface of the liquid from the ultrasound transmitter.
      - • These waves are reflected from the surface of the liquid and are received by the receiver.
      - • In this technique, the differences in the liquid level are measured very precisely by measuring the total time taken by the wave to travel to the liquid and then back to the receiver. (Technical time travel)
      - • The longer these periods fly, the farther away is the liquid surface, which is a measure / indication of the depth of the liquid.
      - • It takes a high degree of expertise and skill to work because the actual instrument is costly.
  - - - Measuring the state of a fluid ( liquid or gas) that is determined by the force that the fluid will exert on a unit area while resting
      - The difference between the two forces, is known as the gauge pressure
      - The differential pressure is indicated by the difference in the level between the two liquid columns and is calculated as the difference in the level multiplied by the density of the liquid
      - The lower pressure is ambient pressure, the total or absolute pressure is the sum of the sensor and ambient pressures.
    - - Bourdon tube
        
        The coiled tube, flattened into the cross-section shown and attached to a fixed block, is opened to the pressurized fluid
      - U-tube manometer
        
        The differential pressure is measured as the difference h between the high-pressure reading and the low-pressure reading, multiplied by the density of the liquid in the tube
  - - - • This signal is provided as input to the machine, electronic circuit, or computer called the controller.
      - • The controller performs the human task of assessing the measurement and providing the output signals, u and v, to adjust the valve setting through the actuator connected to the valve by means of a mechanical connection.
      - • If automatic control is applied to processes designed to control the value of a variable at a fixed stage, it is called process control.
- - - - Mechanism
        
        The liquid level determined by dipping a graduated rod in a liquid.
    - - Mechanism
        
        The liquid level determined by a graduated glass tube mounted on the side of the liquid containing vessel for providing a visual indication of the liquid level.
    - - Mechanism
        
        The liquid level in a large tank determined for accurate measure of a very small changes. A small change in a large tank would mean large volumetric changes.
    - - Mechanism
        
        Consists of float, counter weight and a flexible connection that may be a chain or thin metallic perforated tape
        
        The counter weight keeps the chain/tape taut as the liquid rises or falls with any change in the liquid.
        
        The chain attached on gear/sprocket wheel to which the pointer is attached
        
        Any movement of this wheel would indicate on suitably calibrated scale the level of liquid in tank