Educational Resources

Categories

Classified Areas and Electrical Safety Measures

Classified Areas and Electrical Safety Measures

Any physical location in an industrial facility harboring the potential of explosion due to the presence of…


Textbook

Safety Gas Analyzers

Safety Gas Analyzers

Process analyzers measure the concentration of specific substances for the purpose of measuring and/or…


Textbook

Safety Instrumented Functions and Systems

Safety Instrumented Functions and Systems

A Safety Instrumented Function, or SIF, is one or more components designed to execute a specific…


Textbook

Thermistors and Resistance Temperature Detectors (RTDs)

Thermistors and Resistance Temperature Detectors (RTDs)

One of the simplest classes of temperature sensor is one where temperature effects a change in electrical…


Textbook

Limit, Selector, and Override Controls

Limit, Selector, and Override Controls

Another category of control strategies involves the use of signal relays or function blocks with the ability…


Textbook

Flow Measurement from Differential Pressure

Flow Measurement from Differential Pressure

Take for instance the problem of measuring fluid flow through a pipe. To the layperson, this may seem to be a…


Textbook

Basic Operation of a Gas Chromatograph

Basic Operation of a Gas Chromatograph

This animation shows the basic operation of a gas chromatograph, showing the separation of different molecular…


Textbook

Transformer Basics and Principles of Operation

Transformer Basics and Principles of Operation

The transformer is one of the most important components in all of AC circuitry. Principally used to…


Textbook

Instrument Turndown (Rangedown)

Instrument Turndown (Rangedown)

An important performance parameter for transmitter instruments is something often referred to as turndown or…


Textbook

Differential Pressure Transmitters

Differential Pressure Transmitters

One of the most common, and most useful, pressure measuring instruments in industry is the differential…


Textbook

Problem-solving by Simplification

Problem-solving by Simplification

A whole class of problem-solving techniques focuses on altering the given problem into a simpler form that is…


Textbook

Limit Switches

Limit Switches

A limit switch detects the physical motion of an object by direct contact with that object. An example of a…


Textbook

Different PID Equations

Different PID Equations

For better or worse, there are no fewer than three different forms of PID equations implemented in modern PID…


Textbook

Rotating Phasor in Three-dimensional Form

Rotating Phasor in Three-dimensional Form

The following animation shows a rotating phasor in three-dimensional form. The phasor rotates in a complex…


Textbook

Dimensional Analysis

Dimensional Analysis

An interesting parallel to the “unity fraction” unit conversion technique is something referred to…


Textbook

Rotating Magnetic Fields in Three-phase AC Induction Motors

Rotating Magnetic Fields in Three-phase AC Induction Motors

The following animation shows how the “rotating” magnetic field of a three-phase AC induction…


Textbook

Interconnected Generators

Interconnected Generators

Any power grid large enough to meet the demand of an entire nation must have multiple generators drawing from…


Textbook

Memory Maps and I/O Addressing

Memory Maps and I/O Addressing

A wise PLC programmer once told me that the first thing any aspiring programmer should learn about the PLC…


Textbook

Pneumatic Actuator Response

Pneumatic Actuator Response

A limitation inherent to pneumatic valve actuators is the amount of air flow required to or from the actuator…


Textbook

Process and Instrument Diagrams

Process and Instrument Diagrams

The next level of detail is the Process and Instrument Diagram, or P&ID. Here, we see a “zooming…


Textbook

Velocity-based Flowmeters

Velocity-based Flowmeters

The Law of Continuity for fluids states that the product of mass density (\(\rho\)), cross-sectional pipe area…


Textbook

Introduction to Optical Analysis

Introduction to Optical Analysis

Light is known to interact with matter in very specific ways, which may be exploited as a means of measuring…


Textbook

Understanding the Calculus Concepts of Differentiation and Integration

Understanding the Calculus Concepts of Differentiation and Integration

The following animation shows the calculus concepts of differentiation and integration (with respect to time)…


Textbook

Sliding-stem Valves

Sliding-stem Valves

A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of…


Textbook

Circuit Failure Analysis

Circuit Failure Analysis

Perhaps the most valuable skill an instrument technician can possess is the ability to efficiently diagnose…


Textbook

Ratio Control

Ratio Control

Most people reading this book have likely had the experience of adjusting water temperature using two hand…


Textbook

Calibration Procedures in Linear, Non-Linear and Discrete Instruments

Calibration Procedures in Linear, Non-Linear and Discrete Instruments

As described earlier in this chapter, calibration refers to the adjustment of an instrument so its output…


Textbook

Auxiliary and Lockout (86) Relays

Auxiliary and Lockout (86) Relays

An important type of “accessory” relay, especially for legacy electromechanical protective relays,…


Textbook

Input/Output (I/O) Capabilities of PLCs

Input/Output (I/O) Capabilities of PLCs

Every programmable logic controller must have some means of receiving and interpreting signals from real-world…


Textbook

Functional Diagrams: the Flow of Information within a Control System

Functional Diagrams: the Flow of Information within a Control System

A unique form of technical diagram for describing the abstract functions comprising a control system (e.g. PID…


Textbook

DC Motor Speed Control

DC Motor Speed Control

DC electric motors generate torque by a reaction between two magnetic fields: one field established by…


Textbook

Weight-based Level Measurement

Weight-based Level Measurement

Weight-based level instruments sense process level in a vessel by directly measuring the weight of the vessel.…


Textbook

FOUNDATION Fieldbus H1 Protocol Segment Troubleshooting

FOUNDATION Fieldbus H1 Protocol Segment Troubleshooting

Feedback obtained from industrial users of FF reveal a common pattern: Fieldbus is a powerful and reliable…


Textbook

Level Sensor Accessories

Level Sensor Accessories

Disturbances in the liquid tend to complicate liquid level measurement. These disturbances may result from…


Textbook

Self-balancing Pneumatic Instruments Principles

Self-balancing Pneumatic Instruments Principles

A great many precision instruments use the principle of balance to measure some quantity. Perhaps the simplest…


Textbook

Loop Diagrams (Loop Sheets)

Loop Diagrams (Loop Sheets)

Finally, we arrive at the loop diagram (sometimes called a loop sheet) for the compressor surge control system…


Textbook

Basics of pH Measurement in Industrial Control

Basics of pH Measurement in Industrial Control

Hydrogen ion activity in aqueous (water-solvent) solutions is a very important parameter for a wide variety of…


Textbook

Instantaneous and Time-overcurrent (50/51) Protection

Instantaneous and Time-overcurrent (50/51) Protection

Perhaps the most basic and necessary protective relay function is overcurrent: commanding a circuit breaker to…


Textbook

Proportional-only Control

Proportional-only Control

Imagine a liquid-level control system for a vessel, where the position of a level-sensing float directly sets…


Textbook

Ions in Liquid Solutions

Ions in Liquid Solutions

Many liquid substances undergo a process whereby their constituent molecules split into positively and…


Textbook

The Difference Between Series and Parallel Circuits

The Difference Between Series and Parallel Circuits

In addition to Ohm’s Law, we have a set of rules describing how voltages, currents, and resistances…


Textbook

Control Valve Characterization

Control Valve Characterization

Control valves are supposed to deliver reliable, repeatable control of process fluid flow rate over a wide…


Textbook

Safety Gas Analyzers

Safety Gas Analyzers

Process analyzers measure the concentration of specific substances for the purpose of measuring and/or…


Textbook