Dick Johnson, CONTROL ENGINEERING

Articles

Mechatronics and Motion Control November 2, 2018

Pressure Sensing: It’s Everywhere!

KEY WORDS Process control and instrumentation Process sensing Pressure sensing One of the most-used sensors, pressure instrumentation is found nearly everywhere now. The old process standby is still there—chemical change-of-state monitoring still requires tracking such mundane variables as pressure and temperature—but it now can be found, however tiny, in manufactured goods from au...

By Dick Johnson, CONTROL ENGINEERING
Workforce Development October 1, 2008

Cables and Connectors

Standard twisted pair cable for controller interconnection and "accessories, connectors, and track" were the most often purchased component categories, Control Engineering Product Research shows. See other trends, new products, link to research report.

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors September 3, 2008

Product Research: Flowmeters, users buy more; new technologies

Large amounts of liquid, gas, or slurry feedstocks often require special handling and accurate measurement, a job for modern flowmeter technology. Control Engineering's recent online survey shows an increase in spending on these products, as 24% of respondents plan to increase spending on flowmeters over the next 12 months. See graphics on this research and more product photos.

By Dick Johnson, CONTROL ENGINEERING
Mechatronics and Motion Control September 1, 2008

Programmable Logic Controllers, Programmable Automation Controllers

The 405 respondents who answered the joint Control Engineering/Reed Research product research study on PLCs and PACs will be increasing their purchases of these devices over the next 12 months. Even with the tight economy, 23% of respondents expect their purchases to increase. Of those polled, 69% expected purchases to remain the same as last year, and only 8% expect them to decrease. More trends, PAC and PLC products, and a link to more research follows.

By Dick Johnson, CONTROL ENGINEERING
Mechatronics and Motion Control May 1, 2008

Research results: Protocols for Industrial Ethernet

Need for wide-ranging application capability and the ability to handle diverse environments drives protocol development, sparks user interest, survey results suggest. In Reed Corporate Research studies of control products as recent as five years ago, products using the 4-20 mA standard were still dominating the control scene. That’s changing. Here's how.

By Dick Johnson, CONTROL ENGINEERING
Mechatronics and Motion Control December 1, 2007

Research on Programmable Logic Controllers

Nothing takes the fun out of a control engineering project faster than having to wade through piles of vendor and/or supply house catalogs to find the components for a control system. Even small machine control applications require a lot of specifying, recommending, and purchasing of parts for the simplest of control logic systems—especially if it is to be rendered in traditional relay la...

By Dick Johnson, CONTROL ENGINEERING
Process Safety October 1, 2007

Scales and Load Cells

Weighing technology has been a critical part of industrial activity ever since its earliest development. Simple comparison of materials by weight (whether done with a crude balance or a simple manual comparison—one sample in one hand, one in the other) formed the basis for recipes, inventory measurement, basic custody transfer transactions and determination of selling price.

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors July 1, 2007

Proximity Sensors – 2007-07-01

No matter what they are called—discrete sensors, position sensors, or proximity sensors—they are a mainstay in the factory automation arsenal. They serve in all areas of manufacturing including continuous processing, batch processing, utilities, and discrete products. Technology has changed the mechanical limit switch (rollers, buttons—often teamed up with the mechanically adj...

By Dick Johnson, CONTROL ENGINEERING
Machine Safety June 1, 2007

Using Flowmeters

Beyond just manufacturing and process control, are flowmeters saving technology-based civilization as we know it? In the book, “Flushed: How the Plumber Saved Civilization,” W. Hodding Carter explains in detail the water supply system constructed to supply Rome. “The Empire could tap water 50 miles away, bring it to the city, and then just let it keep on flowing.

By Dick Johnson, CONTROL ENGINEERING
Control Systems January 1, 2004

Data Acquisition Systems Fit Wide-Ranging Applications

Quality data acquisition provides industrial users with the ability to optimize processes, maintain and/or improve product quality, ensure operational safety and environmental compliance, minimize downtime, and improve overall productivity. Control engineers have long depended on accurate data to provide their window into the manufacturing or testing process.

By Dick Johnson, CONTROL ENGINEERING
Edge and Cloud Computing September 1, 2003

Single-board Computers Widely Applied

The single-board computer (SBC) has its roots in the need for application-specific computing power in the control industry. Early designs go back 20 years or more. And although the designs were often based on the idea that an SBC could be just that—a single-board device—board-level component size, power requirements, and the need for expanding systems options often made SBCs only ...

By Dick Johnson, CONTROL ENGINEERING
Diagnostics, Asset Management May 1, 2002

Maintain Level in Granular, Heavy, or Coarse Materials

Keeping track of level in a bin or silo full of solid materials has never been an easy task. The nature of the materials to be sensed conspires to subvert operation of the instrumentation used. Additionally, the medium itself often behaves in a manner that makes obtaining an accurate measurement close to impossible.

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors August 1, 2001

Checking Level: Not Glamorous, Sometimes Dangerous, but Necessary

The amount of level-sensing devices that might "pop up" in any given process plant depends on a number of factors. Level-sensing devices are used to facilitate batch processing, augment process control, track inventory, provide overfill protection, and prevent damage to rotating machinery, such as pumps and motors.

By Dick Johnson, CONTROL ENGINEERING
Vision and Discrete Sensors June 1, 2001

Measuring the Hot, Difficult, and Inaccessible

KEY WORDS Process control and instrumentation Process sensing Noncontact temperature sensing Thermal imaging Imagine yourself dashing out to your car to run a few errands during lunchtime. As you insert the key in the lock, open the door, and swing into the seat, you hardly feel the blast of warm air that greets you—you're in a hurry.

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors February 1, 2001

How to Keep Process Samples Out of the Lab

Inline or is it online? That is the question. No matter what it is referred to as, the idea is the same—get an accurate measurement of process "analyticals" at a point in or near the process stream. Even though the terms have been used interchangeably even in the not-so-recent past, they have evolved separate definitions.

By Dick Johnson, CONTROL ENGINEERING
Machine Safety December 1, 2000

SEEING the LIGHT: Fiber Optics Illuminate Process Control and Instrumentation

Fiber-optic technology—it's not just for decorative lighting anymore. In the 1970s, decorative lighting using fiber-optic cable made a statement (dancing pinheads of ever changing colored light) in college dorm rooms, bachelor pads, and the homes of the avant-garde. What might have been creating really neat novelty lighting at that time was not yet setting the industrial world on fire.

By Dick Johnson, CONTROL ENGINEERING
Industrial Networking October 1, 2000

Hybrid Communication: A Closer Look at HART

Do you feel stuck with the old 4-20 mA-based control system that was installed when the process plant was built? The original system, which was state-of-the-art when originally put in, wasn't designed to supply all information necessary to streamline the process and breathe profitability into the now old facility.

By Dick Johnson, CONTROL ENGINEERING
Process Safety September 1, 2000

Differential Flowmeters: Simple Can Be Better

In 1502, Leonardo da Vinci noted, "A river in each part of its length in an equal time gives passage to an equal quantity of water, whatever the width, the depth, the slope, the roughness, the tortuosity." This simple observation provided the basis for simple flow measurement—the principle of continuity.

By Dick Johnson, CONTROL ENGINEERING
Machine Safety July 1, 2000

Keeping the ‘Explosion Genie’ in the Bottle

Many industries must routinely deal with materials that explode, burn, or explode and burn. Actually, explosions in gas, vapors, or dusts are not detonations but very rapid burning of the media best described as deflagrations. Handling "media from hell" often requires many specialized equipment and disciplines (everything from mechanical system design to satisfying numerous industry assoc...

By Dick Johnson, CONTROL ENGINEERING
Vision and Discrete Sensors March 1, 2000

Weighing Technology Can Be Pretty Heavy Stuff

Determining the weight of a quantity of process media is a necessary part of many process applications. Weight can be used to infer the level of both liquids and bulk solids in hoppers and bins. Weighing is a necessary function in batch operations because recipes usually call for ingredients to be combined by weight.

By Dick Johnson, CONTROL ENGINEERING
Control Systems September 1, 1999

Smaller SCADA Dial-up Environmental Protection

Keeping pollution within U.S. Environmental Protection Agency (EPA) guidelines remains of great concern, and the engineering team often takes lead responsibilities for preventing environment-fouling releases. Although it may be scrubbers or physical containment that are needed for meeting actual requirements, the systems' monitoring and documentation system usually holds the most interes...

By Dick Johnson, CONTROL ENGINEERING
Energy, Power September 1, 1999

Open Systems in Process Control Are They the Answer?

Free mixing of hardware and software to solve control problems has advantages, but only when it works.Finding a single definition for the term "open system" is a thorny problem. In an open system, control engineers should be able to take appropriate control hardware (sensors, controllers, PCs, cabling, etc.

By Dick Johnson, CONTROL ENGINEERING
Mechatronics and Motion Control July 1, 1999

Pneumatic control: Testbed for Ziegler-Nichols tuning

Up until 1940, controller tuning was an art conducted by seat-of-the-pants methods. At the Taylor Instrument Co. (then Rochester, N.Y.), engineers John G.

By Dick Johnson, CONTROL ENGINEERING
Machine Safety July 1, 1999

Pneumatic Control: Not Dead Yet

Pneumatic control may be considered a dinosaur, but it is still walking this Earth very much alive. The predecessor of the "beloved" 4-20 mA standard, pneumatics has remained "active" in many process industries, even though it now often shares the spotlight in hybrid analog control systems. Even though control has slowly edged its way into the digital era, it has adapted to newer surroun...

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors June 1, 1999

Leveraging Multivariable Sensing

Long ago in the realm of process control, engineers had few options for gathering process variable data, especially if information had to be monitored within a confined area. Sensors and their associated electrical wiring and componentry were physically large, cumbersome, and not terribly sophisticated.

By Dick Johnson, CONTROL ENGINEERING
Energy, Power April 1, 1999

Fitting the Instrument Into the Process

The "nuts and bolts" issues that crop up in instrument integration can take a back seat to high-tech specifications. Although mounting issues seem mundane, they can figure prominently into overall success of an instrument's commissioning.General guidelines for the "big four" (pressure, temperature, level, and flow) vary little from one manufacturer to another.

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors February 1, 1999

How to Deliver Liquids and Gases Accurately

In the industrial world, the term custody transfer does not refer to what happened to Dustin Hoffman's "screen" son in the Academy Award winning film "Kramer vs. Kramer." Instead, it describes a method for keeping track of quantities of fluids—liquids, gases, slurries—as they are moved between two locations.

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors December 1, 1998

Ethernet Edges toward Process Control

Is Ethernet the solution for industrial networking, or will it create additional problems? According to a white paper published in April 1998 by Rockwell International Corp., "Ethernet's worldwide acceptance in industrial and office environments has created eagerness to expand its responsibilities on the plant floor.

By Dick Johnson, CONTROL ENGINEERING
PID, APC November 1, 1998

Process Instrumentation’s ‘Utility Infielder’

This is the final installment of a five-part series on Process Sensing. Pressure sensing appeared in March. Smart sensors appeared in May. Other articles included temperature sensing (June) and flow measurement (September).It is probably safe to say that process automation has been applied in some way or another to every industry.

By Dick Johnson, CONTROL ENGINEERING
PID, APC September 1, 1998

Flow Switch Features Easy Setup

Accurate setup is perhaps the most time consuming and tedious aspect of an instrument technician's job. Calibration requires that settings be checked against known conditions so that readings are meaningful to the process.In the case of an component like a flow switch, determining setpoints requires a technician to know limiting flow rates and pick devices accordingly.

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors June 1, 1998

Contact Sensors: The Business End of Temperature Measurement

This is the third installment of a five-part series on Process Sensing. Pressure sensing appeared in March. Smart sensors appeared in May. Other articles include flow measurement (September) and level sensing (November).Unsung. Unremarked. Easily forgotten but definitely indispensable. They come in a myriad of sizes and packages.

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors May 1, 1998

Process Control Goes ‘Off to See the Wizard’

This is the second installment of a five-part series on Process Sensing. Pressure sensing appeared in March. Others include temperature sensing (June), flow measurement (September), and level sensing (November).If you really want to stir up some controversy in the control room or up in the engineering department, get on the subject of smart sensors.

By Dick Johnson, CONTROL ENGINEERING
Process Instrumentation and Sensors March 1, 1998

Keeping the Pressure On Pressure Instrumentation

This is the first installment of a five-part series on Process Sensing. Smart sensors will appear in May. Others include temperature sensing (June), flow measurement (September), and level sensing (November).Temperature may be the most measured process variable, but pressure sensing devices may be the most ubiquitous.

By Dick Johnson, CONTROL ENGINEERING