Funda ppt 1

• INSTRUMENTATION

  ➢branch of physics which deals with the measuring, monitoring and controlling

  variables in a process industry.
• INSTRUMENT

  ➢device that measures, monitors and control process variables.
• Critical

  ➢ An instrument which, if not conforming to specification, could potentially compromise product or process quality and safety
• Non-critical

  ➢ An instrument whose function is not critical to product or process quality, but whose function is more of an operational significance.
• Reference Only

  ➢ An instrument whose function is not critical to product quality, not significant to equipment operation, and not used for making quality decisions.
• CONTROL

  ➢in process industries it refers to the regulation, command or direction of all aspects of the process.
• 2 Types of Control:

  • Manual Control

  • Automatic Control
• PROCESS

  ➢refers to the methods of changing or refining raw materials to create end products.
• PROCESS CONTROL

  ➢ the regulation or manipulation of variables influencing the conduct of a process in such a way as to obtain a product of desired quality and quantity in an efficient manner.
• SYSTEM

  ➢ an arrangement, set or collection of physical components connected or related in such a manner as to form and/or act as an entire unit
• CONTROL SYSTEM

  ➢ an arrangement of physical components connected or related in such a manner as to command, direct or regulate itself or another system.
• INSTRUMENTATION SYSTEM

  ➢ an arrangement of two or more instruments connected together to perform a unified task.
• CONTROL LOOP

  ➢a process management system designed to maintain a process variable at a desired set point.
• Closed Control Loop – exists when a process variable is measured, compared to a setpoint and action is taken to correct any deviation from setpoint.
• Open Control Loop – exist when the process variable is not compared, and action is taken not in response to on the condition of the process variable.
• Setpoint – a value for a process variable that is desired to be maintained.
• ELEMENTS of the INSTRUMENT LOOP

  1. Process

  2. Measuring Element

  3. Receiving Element

  4. Final Control Element
• Process

  Any operations or sequence of operations involving a change of energy, state, composition, dimension or other properties that may be defined with respect to a datum/data.
• Process Variable- any variable property of a process
• Set point (SP)- any input variable that seats the desired value of the measured variable.
• Controller Output – outputs signal generated in response to a change of a process

  variable.
• Manipulated variable- a process variable linked to the controller output that is used to

  influence the measured variable.
• Instrument Loop

  A combination of two or more instruments or control functions arranged so that signal pass from one to another for the purpose of measurement and/or control of a process variables.
• Process Control

  The regulation or manipulation of variables influencing the conduct of a process in such a way as to obtain a product of desired quality and quantity in an efficient manner.
• Measurement: The determination of the

  magnitude of a variable (VALUE)
• Detection: The determination of the existence or the presence of a variable.