Process Control Variables Training

603-01 Instrumentation and Control Overview

When you complete this lesson, you will be able to describe the basic operating principles behind the instrumentation and control common to your unit. You will also be able to identify various instrumentation components and discuss the ways instrumentation systems collect and transmit information.

  • Discuss the importance of instrumentation and control
  • Define the following common plant process variables:
    • Pressure
    • Temperature
    • Flow
    • Level
    • Analytical
  • Describe basic function of process instrumentation
  • Explain the relationship between common process variables
  • Define terms associated with process instrumentation:
    • Differential (delta ∆)
    • Local control
    • Remote control
    • Control loop
    • Electronic
    • Pneumatic
    • Analog
    • Digital

603-02 Principles of Temperature

When you complete this lesson, you will understand the concepts of temperature and heat transfer and be able to convert between common temperature scales.

  • Define heat and temperature and explain the difference between them
  • Recognize different temperature scales and list their basic units of measurement
  • Convert between common temperature scales
  • Describe how heat transfer can change the temperature or other physical properties of a substance
  • Describe the following methods of heat transfer:
    • Conduction
    • Convection
    • Radiation

603-03 Principles of Pressure

When you complete this lesson, you will understand pressure and how it is measured. You will be able to apply conversion formulas to convert readings from one standard pressure scale to another.

  • Define pressure and list the basic units of pressure measurement
  • Discuss the formula used to calculate pressure (P = F/A)
  • List the factors and conditions that affect pressure
  • Explain how Boyle’s Law and the combined gas law relate to pressure
  • Recognize common pressure measurement scales and demonstrate your ability to calculate conversion between them

603-04 Principles of Level

When you complete this lesson, you will be able to explain the concept of level and describe how it is measured.

  • Define level
  • Explain the difference between continuous and single-point level detection
  • List the basic units of level measurement
  • Define the following terms associated with level measurement:
    • Innage
    • Ullage (outage)
    • Level
    • Interface
    • Meniscus
    • Buoyancy

603-05 Principles of Flow

When you complete this lesson, you will be able to describe the principles of fluid flow and understand how these principles provide multiple means for measuring flow rate in the process industry.

  • Define flow rate
  • Discuss the difference between volumetric and mass flow rate and list the common units used for measuring each
  • Describe the common types of flow measuring devices used in industrial processes
  • Using the concept of flow profiles, explain laminar and turbulent flow including a discussion of Reynolds Numbers
  • Explain how flow rate is affected by the following fluid properties:
    • Pressure
    • Density
    • Viscosity
  • Describe how detector position and flow disturbances can affect the accuracy of flow rate measurements

603-06 Temperature Instruments

When you complete this lesson, you will be able to identify various temperature measuring and sensing devices, and describe their operation.

  • Describe and give examples of the following types of temperature measuring devices:
    • Thermal Expansion Thermometers
    • Electrical Thermometers
    • Infrared Radiation Thermometers
  • Explain the operation of a resistance temperature detector (RTD) and bridge circuit
  • Describe how to properly connect a 2-wire or 3-wire RTD to a temperature transmitter
  • Describe how temperature is measured using a thermocouple
  • Explain thermocouple compensation and the effect of wires and junctions on accurate temperature measurement
  • Describe distance-to-size ratio in an infrared radiation thermometer
  • Explain emissivity in relation to an infrared radiation thermometer

603-07 Pressure Measuring Devices

When you complete this lesson, you will be able to identify and describe the operation of various pressure sensing and measurement devices.

  • Describe the difference between absolute, gauge, vacuum, and differential pressure
  • Describe and explain the operation of liquid column manometers, including the following types:
    • U-tube
    • Well
    • Inclined tube
  • Describe and explain the operation of elastic pressure sensors, including the following types:
    • Bourdon tube
    • Bellows
    • Diaphragm
  • Explain in detail the construction and operation of a Bourdon tube pressure gauge
  • Describe the purpose of a pressure switch, pressure transducer, and a d/p cell

603-08 Level Measuring Devices

When you complete this lesson, you will be able to identify various level sensing and measurement devices, and describe their basic operation.

  • Describe the basic types of level measurements, including point and continuous level methods
  • Explain the operation of the following types of direct measuring level instruments:
    • Weighted tape gauge
    • Sight glass
    • Reflex gauge glass
    • Float
  • Explain the operation of the following types of indirect measuring level instruments:
    • Pressure detector
    • Bubbler
    • Displacer
    • Capacitance probe
    • Ultrasonic/radiation sensor
    • Weight sensor

603-09 Flow Measuring Devices

When you complete this lesson, you will be able to identify and describe the basic operation of various direct and indirect flow measurement devices.

  • Describe the following types of flow measuring devices, or flowmeters:
    • Mass flowmeters
    • Velocity based flowmeters
    • Variable area flowmeters
    • Pressure based flowmeters
  • Explain how a Coriolis flowmeter and a thermal flowmeter determine mass flowrate
  • Describe the operation of the following velocity based flowmeters:
    • Turbine flowmeter
    • Vortex flowmeter
    • Magnetic flowmeter
    • Ultrasonic flowmeter
    • Optical flowmeter
  • Explain how a rotameter uses variable flow area to determine flowrate
  • Explain how differential pressure can indirectly indicate flowrate
  • Describe the following methods for producing a differential pressure that are commonly used in flow measuring instruments:
    • Orifice plates
    • Venturi tubes
    • Flow nozzles
    • Pitot tubes
  • Describe the difference between and give examples of concentric and non-concentric orifice plates

603-15 Weight Measuring Devices

When you complete this lesson, you will be able to describe various weight measuring devices used in industrial applications and explain their operating principles.

  • Identify the two types of balance scales
  • Describe platform scales
  • Describe stretched and compressed spring scales
  • Explain the operation of electronic, hydraulic, and pneumatic load cells
  • Explain the operation of linear variable differential transformers
  • Describe batch and belt scales, including continuous weigh feeders and nuclear scales