Educational Resources

Categories

Colorimetric and Potentiometric pH Measurement

Colorimetric and Potentiometric pH Measurement

pH is the measurement of the hydrogen ion activity in a liquid solution. It is one of the most common forms of…


Textbook

Thermocouple Types, Junctions, Connector and Tip Styles

Thermocouple Types, Junctions, Connector and Tip Styles

RTDs are completely passive sensing elements, requiring the application of an externally-sourced electric…


Textbook

Introduction to Modbus

Introduction to Modbus

Developed by the Modicon company (the original manufacturer of the Programmable Logic Controller, or PLC) in…


Textbook

Digital Data Communication Theory

Digital Data Communication Theory

One of the great benefits of digital technology is the ability to communicate vast amounts of information over…


Textbook

EIA/TIA-232, 422, and 485 Networks

EIA/TIA-232, 422, and 485 Networks

Some of the simplest types of digital communication networks found in industry are defined by the EIA…


Textbook

4-wire “Passive” Versus “Active” Output Transmitters

4-wire “Passive” Versus “Active” Output Transmitters

Some self-powered (4-wire) analog electronic transmitters are designed to behave as electrical loads rather…


Textbook

Design-based Fortifications

Design-based Fortifications

A design-based fortification is one rooted in technical details of system architecture and functionality. Some…


Textbook

Thermocouple Types, Junctions, Connector and Tip Styles

Thermocouple Types, Junctions, Connector and Tip Styles

RTDs are completely passive sensing elements, requiring the application of an externally-sourced electric…


Textbook

Colorimetric and Potentiometric pH Measurement

Colorimetric and Potentiometric pH Measurement

pH is the measurement of the hydrogen ion activity in a liquid solution. It is one of the most common forms of…


Textbook

Digital PID Controllers

Digital PID Controllers

The vast majority of PID controllers in service today are digital in nature. Microprocessors executing PID…


Textbook

Electrical Signal and Control Wiring

Electrical Signal and Control Wiring

There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…


Textbook

What is Internet Protocol (IP)?

What is Internet Protocol (IP)?

I remember first learning about the world-wide Internet, and wondering what it actually looked like. The first…


Textbook

Ethernet networks: Repeaters, Cabling and Switching Hubs

Ethernet networks: Repeaters, Cabling and Switching Hubs

An engineer named Bob Metcalfe conceived the idea of Ethernet in 1973, while working for the Xerox research…


Textbook

How to Teach Yourself PLC Programming

How to Teach Yourself PLC Programming

Learning PLC programming is a very important skill. If your job involves programming, then you will likely…


Textbook

2-wire (“loop-powered”) Transmitter Current Loops

2-wire (“loop-powered”) Transmitter Current Loops

It is possible to convey electrical power and communicate analog information over the same two wires using 4…


Textbook

FOUNDATION Fieldbus H1 Protocol Physical Layer

FOUNDATION Fieldbus H1 Protocol Physical Layer

Layer 1 of the OSI Reference Model is where we define the “physical” elements of a digital data…


Textbook

4-wire (“self-powered”) Transmitter Current Loops

4-wire (“self-powered”) Transmitter Current Loops

DC electric current signals may also be used to communicate process measurement information from transmitters…


Textbook

Teaching Technical Practices (Labwork)

Teaching Technical Practices (Labwork)

Labwork is an essential part of any science-based curriculum. Here, much improvement may be made over the…


Textbook

Examples of PLC Systems

Examples of PLC Systems

Programmable logic controllers are essentially nothing more than special-purpose, industrial computers. As…


Textbook

Fiber Optic Data Communication

Fiber Optic Data Communication

Light has long been used as a long-range signaling medium. While communication by light through open air is…


Textbook

Distance (21) Protection

Distance (21) Protection

A form of protection against faults on long-distance power lines is called distance relaying, so named because…


Textbook

Ultrasonic (Sound) Echo Level Measurement

Ultrasonic (Sound) Echo Level Measurement

A completely different way of measuring liquid level in vessels is to bounce a traveling wave off the surface…


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

Digital PID Algorithms

Digital PID Algorithms

Instrument technicians should not have to concern themselves over the programming details internal to digital…


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

4 to 20 mA Analog Current Signals

4 to 20 mA Analog Current Signals

The most popular form of signal transmission used in modern industrial instrumentation systems (as of this…


Textbook

Gas Filter Correlation (GFC) Spectroscopy

Gas Filter Correlation (GFC) Spectroscopy

Using filter cells to eliminate wavelengths associated with interfering gases is called positive filtering in…


Textbook

Radio-energy Pulse in Guided-wave Radar Level Measurement

Radio-energy Pulse in Guided-wave Radar Level Measurement

The following animation shows how a radio-energy pulse travels down and then up the waveguide of a guided-wave…


Textbook

Differential (87) Current Protection

Differential (87) Current Protection

One of the fundamental laws of electric circuits is Kirchhoff’s Current Law, which states the algebraic…


Textbook

What are Simple Machines?

What are Simple Machines?

A machine in the broad sense of the word is any device designed to translate some form of energy into useful…


Textbook

Ladder Diagram (LD) Structure Commands

Ladder Diagram (LD) Structure Commands

The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…


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

Kirchhoff’s Current and Voltage Laws

Kirchhoff’s Current and Voltage Laws

Two extremely important principles in electric circuits were codified by Gustav Robert Kirchhoff in the year…


Textbook

4-wire “Passive” Versus “Active” Output Transmitters

4-wire “Passive” Versus “Active” Output Transmitters

Some self-powered (4-wire) analog electronic transmitters are designed to behave as electrical loads rather…


Textbook

Derivative (Rate) Control

Derivative (Rate) Control

The final element of PID control is the “D” term, which stands for derivative. This is a calculus…


Textbook

Advantages and Disadvantages of Pneumatic Instruments

Advantages and Disadvantages of Pneumatic Instruments

The disadvantages of pneumatic instruments are painfully evident to anyone familiar with both pneumatic 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

Applications of Spectroscopy for Analytical Measurement

Applications of Spectroscopy for Analytical Measurement

Much of our knowledge about atomic structure comes from experimental data relating the interaction between…


Textbook

AC Motor Braking

AC Motor Braking

There are several different methods useful for causing an AC induction motor to brake, or slow down: DC…


Textbook

FOUNDATION Fieldbus H1 Protocol Physical Layer

FOUNDATION Fieldbus H1 Protocol Physical Layer

Layer 1 of the OSI Reference Model is where we define the “physical” elements of a digital data…


Textbook