At the root of successful system diagnosis is a rigorous adherence to scientific reasoning. There exists no…
Textbook
As a general rule, high achievement only takes place in an atmosphere of high expectations. Sometimes these…
Textbook
A variety of technologies exist to measure the quantity of stored material in a vessel. For liquid…
Textbook
So far we have just looked at instruments that sense, control, and influence process variables. Transmitters,…
Textbook
A wise PLC programmer once told me that the first thing any aspiring programmer should learn about the PLC…
Textbook
Process analyzers measure the concentration of specific substances for the purpose of measuring and/or…
Textbook
First, let us review some of the properties of differentials and derivatives, referencing the expression and…
Textbook
One of the simplest classes of temperature sensor is one where temperature effects a change in electrical…
Textbook
Light is known to interact with matter in very specific ways, which may be exploited as a means of measuring…
Textbook
Current is the name we give to the motion of electric charges from a point of high potential to a point of low…
Textbook
Phasors are to AC circuit quantities as polarity is to DC circuit quantities: a way to express the…
Textbook
Valve actuators provide force to move control valve trim. For precise positioning of a control valve, there…
Textbook
Thermodynamics is the study of heat, temperature, and their related effects in physical systems. As a subject,…
Textbook
DC electric current signals may also be used to communicate process measurement information from transmitters…
Textbook
One of the most common, and most useful, pressure measuring instruments in industry is the differential…
Textbook
A technological advance introduced in the late 1980’s was HART, an acronym standing for Highway…
Textbook
AC induction motors are based on the principle of a rotating magnetic field produced by a set of stationary…
Textbook
I remember first learning about the world-wide Internet, and wondering what it actually looked like. The first…
Textbook
Capacitors store energy in electric fields, proportional to the square of voltage. Inductors store energy in…
Textbook
Valves can experience a number of problems, most of them either preventable or repairable. These problems can…
Textbook
Much of our knowledge about atomic structure comes from experimental data relating the interaction between…
Textbook
As defined previously, calibration means the comparison and adjustment (if necessary) of an instrument’s…
Textbook
Human-machine interfaces, or HMIs, are a critical part of nearly all control systems, complementing the…
Textbook
One of the great benefits of digital technology is the ability to communicate vast amounts of information over…
Textbook
Instrument technicians should not have to concern themselves over the programming details internal to digital…
Textbook
An electromechanical relay is an electrical switch actuated by an electromagnet coil. As switching devices,…
Textbook
Perhaps the most confusing aspect of discrete sensors is the definition of a sensor’s normal status.…
Textbook
A bridge circuit is basically a pair of voltage dividers where the circuit output is taken as the difference…
Textbook
Filled-bulb systems exploit the principle of fluid expansion to measure temperature. If a fluid is enclosed in…
Textbook
The purpose of a control valve actuator is to provide the motive force to operate a valve mechanism. Both…
Textbook
Tube, like pipe, is a hollow structure designed to provide an enclosed pathway for fluids to flow. In the case…
Textbook
The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…
Textbook
In the United States, the ANSI and IEEE organizations have standardized a set of numerical codes referring to…
Textbook
RTDs are completely passive sensing elements, requiring the application of an externally-sourced electric…
Textbook
Some analyzers measure the composition of a process stream by directly immersing the sensing element in that…
Textbook
By definition, a source is a device delivering energy into a system, while a load is a device extracting…
Textbook
Those familiar with industrial instrumentation will find much within the electric power industry remarkably…
Textbook
The advent of “smart” field instruments containing microprocessors has been a great advance for…
Textbook
Current is the name we give to the motion of electric charges from a point of high potential to a point of low…
Textbook
Virtually any mass above absolute zero temperature emits electromagnetic radiation (photons, or light) as a…
Textbook
The efficient identification and correction of instrument calibration errors is an important function for…
Textbook
“Radio” systems use electromagnetic fields to communicate information over long distances through…
Textbook
An important type of “accessory” relay, especially for legacy electromechanical protective relays,…
Textbook
A simple control system drawn in block diagram form looks like this: Information from the measuring device…
Textbook
An important performance parameter for transmitter instruments is something often referred to as turndown or…
Textbook
The final step in treating wastewater before releasing it into the natural environment is to kill any harmful…
Textbook
When I began teaching full-time in 1998, most of what I thought I understood about good teaching was actually…
Textbook
A hand switch is exactly what the name implies: an electrical switch actuated by a person’s hand motion.…
Textbook
A laser is a light source emitting waves of light that not only share the exact same frequency (color)…
Textbook
The digital multimeter (DMM) is quite possibly the most useful tool in the instrument technician’s…
Textbook
Most pneumatic instruments use a simple but highly sensitive mechanism for converting mechanical motion into…
Textbook
Negative feedback systems, in general, tend to cause confusion for those first learning their fundamental…
Textbook
Electrical power grids primarily consist of three-phase AC circuits. This means most power lines (transmission…
Textbook
A vertical column of fluid generates a pressure at the bottom of the column owing to the action of gravity on…
Textbook
The term “grid” refers to the conductors and equipment interconnecting power sources to power…
Textbook
In the United States, the most common language used to program PLCs is Ladder Diagram (LD), also known as…
Textbook
Learning how to tune PID controllers is a skill born of much practice. Regardless of how thoroughly you may…
Textbook
These fortifications focus on human behavior rather than system design or component selection. In some ways…
Textbook
Control valves are supposed to deliver reliable, repeatable control of process fluid flow rate over a wide…
Textbook
For better or worse, there are no fewer than three different forms of PID equations implemented in modern PID…
Textbook
Facebook
Google
GitHub
Linkedin