“Control system power and grounding is possibly the single most important element to ensure a control system doesn’t experience unidentified ‘gremlins’ throughout its life,” says Dave Harrold, Control Engineering’s consulting editor.
Before replacing an aging control system, the engineer willing to conduct a forensic examination increases the odds the new system will perform reliably. See power and grounding tips.
JUNE 28, 2005 TECH TIP OF THE WEEK: When to use RTDs or thermocouples. Quick selection guidelinesRTDs Offer stable output within broad temperature ranges; Can be recalibrated for verifiable accuracy; Are stable over the long term; Follow a more linear curve than thermocouples; Have high sensitivity; and Provide accurate reading over narrow temperature spans. Thermocouples: Operate at temperatures over 1,200°F (648.88°C); Perform in extremely rugged applications; Offer very fast response to temperature changes; Are small in physical size; and May have a lower initial cost in some applications. The two most common ways of measuring industrial temperatures are with resistance temperature detectors (RTDs) and thermocouples. But when should control engineers use a thermocouple and when should they use an RTD? The answer is usually determined by four factors: temperature, time, size, and overall accuracy requirements. What are the temperature requirements? If process temperatures fall from -328 to 932°F (-200 to 500°C), then an industrial RTD is an option.
MAY 31, 2005 TECH TIP OF THE WEEK: Learning level-sensing technologies. There are many different ways to measure the level of products in industrial storage and process vessels. One of the most commonly used devices is the differential pressure (dp) transmitter.
APRIL 26, 2005 TECH TIP OF THE WEEK: Systems possibly subject to FDA 21 CFR Part 11. Systems possibly subject to the U.S. Food and Drug Administration's (FDA) 21 CFR Part 11 regulations include: Laboratory Stability systemsToxicology systemsLaboratory robotic systemsEnvironmental monitoring systemsLaboratory instruments with data acquisition capabilityLaboratory information systemsOther data acquisition systems Clinical Case report form systemsClinical data management systemsRemote data entry systemsRemote data capture systemsAdverse event reporting systemsOther data acquisition systems Manufacturing Manufacturing execution systemsMaintenance management systemsCalibration management systemsBuilding management systemsEnterprise resource planning systemsControl and automation systemsOther data acquisition systems Quality Document management systemsGood practices and other product tracking systemsStandard operating procedure systemsOther data acquisition systems Dave Harrold, contributing editor Source: Dave Harrold, 'I'm from the Government and I'm Here to Help You,' Control Engineering, April '02, p.
Proper grounding keeps the gremlins out of automation and controls, when appropriate installation practices are followed. Here are 10 tips for better grounding.
Oak Brook, IL—Control System Power and Grounding Better Practice, by David Brown, David Harrold and Roger Hope, is a new book published by Control Engineering, Elsevier/Newnes and Reed Business Information.
2004 is shaping up to be a special year for Control Engineering in many ways. For starters, it is our 50th anniversary and we will be celebrating it throughout the year. 2004 is also the first full year of publication under our new design and guidance, and we will be debuting new columns and sections.
Sense, decide, and act are the three cornerstones of the control and automation field and its many related industries and applications. Similarly, the three cornerstones of the Control Engineering2003 Editors' Choice Awards are service to the industry, technological advancement, and market impact. Seven editors—Frank Bartos, David Greenfield, Dave Harrold, Mark Hoske, Jeanine Katzel, Ji...
Flowserve recently introduced its new Multi-Z severe service control valve. Flowserve spokespersons say the Multi-Z is designed to handle high-pressure drop applications where entrained solids are a problem, and is suited for system start-up and boiler-feed water recirculation applications.
Honeywell recently announced it has been selected to negotiate a $10 million project, co-funded by the U.S. Department of Energy (DOE), to develop wireless sensor technologies that can meet plant floor operational control challenges.
By the time you read this, I’ll have begun my retirement. Yeah, I know, many of you are saying, "Oh, he’s much too young to retire." Thanks, you’re very kind.
Anyone who’s made a confined space entry will appreciate the M40 multi-gas detector recently introduced by Industrial Scientific. The M40 is capable of simultaneously measuring carbon monoxide, hydrogen sulfide, oxygen, and combustible gases and is suited for a wide variety of confined space and personal monitoring applications.
In my October 2003 article (p.46) titled, "XML Delivers" I wrote about two early adopters of the ANSI/ISA S95 standard "Enterprise-control system integration," Empresas Polar in Caracas, Venezuela, and Europe-based Arla Foods. In addition to adopting the ANSI/ISA S95 standard, both companies also embraced early versions of the World Batch Forum’s (WBF) B2MML (batch to manufacturing markup language.)
Emerson Process Management’s Fisher division recently added "green-yellow-red light" performance diagnostics capability to its Fieldvue digital valve controller.
Density, specific gravity and percent concentration are important gas measurements throughout the crude oil refining process. Conoco-Phillips' Roxanna and BP's Texas City are among the refineries using Yokogawa's GD402 gas analyzer.
Anyone using National Instruments (NI) LabView software should consider downloading free thermocouple calibration software that NI spokespersons say improves the accuracy of thermocouple measurements by as much as 400%.
Fieldbus Foundation is making available its FOUNDATION fieldbus System Engineering Guide. Available as a free downloadable PDF file, this is a comprehensive (101 page) document which describes the design, specification, installation, configuration, commissioning, and maintenance of FOUNDATION fieldbus-based control systems.
It looks like this must be the time of year for learning, at least that's the conclusion I arrived at after looking over my recent e-mails promoting Web and in-person seminars and training classes.
Last month I mentioned an e-Bay like site called ClassicAutomation.com where people could buy and sell industrial control components. Last month's e-newsletter had been out less than an hour when I heard from Rick Zabel at AutomationTechies.com.
Within the newest version of OSIsoft's PI BatchView, users have access to a hierarchical representation of repeatable process events. A process variable can be displayed as a batch event, and compared to hundreds of similar events, in order to verify process repeatability.
Trevor Kletz is a well-known expert on process safety. His first book, ''What Went Wrong?'' revolutionized the way the process industry views safety. Kletz's latest book, ''Still Going Wrong!'' examines case histories of process plant disasters and how they could have been avoided.
If you’re doing an OPC implementation, especially if it's your first, you will soon learn two very important things:1) OPC client and server tags must be a perfect match, including the full path, or things don’t work; and 2) DCOM (distributed component object model) can be fickle.
Houston, TX—Developed using sonar array technology, Cidra’s Sonartrac flow monitoring system provides a non-intrusive means of accurately and repeatedly measuring single and multi-phased medias including pulp slurry, sewage, and those with entrained air
In the March 2003 issue of Control Engineering, I wrote an article titled “Get safe: Prepare for Security Intrusion.” In that article I outlined a means for strengthening control system security against cyber-attacks. A lot of the article content came from conversations with Larry Falkenau of DuPont Engineering.