By definition, a source is a device delivering energy into a system, while a load is a device extracting…
Textbook
A fundamental principle in instrumentation system troubleshooting is that every instrument has at least one…
Textbook
The digital multimeter (DMM) is quite possibly the most useful tool in the instrument technician’s…
Textbook
As previously defined, calibration refers to the checking and adjustment of an instrument so that its output…
Textbook
An important type of “accessory” relay, especially for legacy electromechanical protective relays,…
Textbook
Linearity of Measurement Instruments The purpose of calibration is to ensure the input and output of an…
Textbook
An electromechanical relay is an electrical switch actuated by an electromagnet coil. As switching devices,…
Textbook
A completely different way of measuring liquid level in vessels is to bounce a traveling wave off the surface…
Textbook
The two “process variables” we rely on most heavily in the field of electrical measurement and…
Textbook
A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of…
Textbook
Feedback Control System Components Before we begin our discussion on process control, we must define a few key…
Textbook
The Law of Continuity for fluids states that the product of mass density (\(\rho\)), cross-sectional pipe area…
Textbook
Regardless of valve type, all stem-actuated control valves require some form of seal allowing motion of the…
Textbook
A number of different sensors used in instrumentation generate DC voltage signals proportional to the process…
Textbook
Tube, like pipe, is a hollow structure designed to provide an enclosed pathway for fluids to flow. In the case…
Textbook
Imagine a liquid-level control system for a vessel, where the position of a level-sensing float sets the…
Textbook
In some process applications, it is important that the control valve be able to completely stop fluid flow…
Textbook
A pneumatic controller receives a process variable (PV) signal as a variable air pressure, compares that…
Textbook
Control strategies such as cascade, ratio, feedforward, and those containing limit and selector functions can…
Textbook
Imagine a liquid-level control system for a vessel, where the position of a level-sensing float directly sets…
Textbook
A very simple device used to measure pressure is the manometer: a fluid-filled tube where an applied gas…
Textbook
In order for any PID controller to be practical, it must be able to do more than just implement the PID…
Textbook
Disconnect Switches Disconnects are switches designed to isolate sections of a power system in case of damage…
Textbook
As described earlier in this chapter, calibration refers to the adjustment of an instrument so its output…
Textbook
The next level of detail is the Process and Instrument Diagram, or P&ID. Here, we see a “zooming…
Textbook
An important type of “accessory” relay, especially for legacy electromechanical protective relays,…
Textbook
A bridge circuit is basically a pair of voltage dividers where the circuit output is taken as the difference…
Textbook
Once while working as an instrument technician in an aluminum foundry, a mechanic asked me what it was that I…
Textbook
One of the marks of a successful problem-solver is a habit of applying general principles to every new problem…
Textbook
(Will be addressed in future versions of this book)
Textbook
Light has long been used as a long-range signaling medium. While communication by light through open air is…
Textbook
In the United States, the most common language used to program PLCs is Ladder Diagram (LD), also known as…
Textbook
Many years ago, when I was first learning about electricity, I happened to discover a length of coaxial…
Textbook
As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two…
Textbook
An variable-area flowmeter is one where the fluid must pass through a restriction whose area increases with…
Textbook
A unique form of differential pressure-based flow measurement deserves its own section in this flow…
Textbook
A level switch is one detecting the level of liquid or solid (granules or powder) in a vessel. Level switches…
Textbook
First, let us review some of the properties of differentials and derivatives, referencing the expression and…
Textbook
This section shows some of the many instrument symbols found in different types of technical diagrams used to…
Textbook
Fluid pressure exerts force on any surface area it contacts, as described by the formula \(F = PA\). One…
Textbook
Instrument technicians should not have to concern themselves over the programming details internal to digital…
Textbook
All masses require force to accelerate (we can also think of this in terms of the mass generating a reaction…
Textbook
Mechanical pressure-sensing elements include the bellows, the diaphragm, and the bourdon tube. Each of these…
Textbook
Solids tend to expand when heated. The amount that a solid sample will expand with increased temperature…
Textbook
Facebook
Google
GitHub
Linkedin