Dick Johnson, CONTROL ENGINEERING
Articles
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...
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.
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.
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.
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.
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...
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.
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...
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.
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.