Control Engineering’s Process Instrumentation Enews — April 2001

By Dick Johnson May 30, 2002

In this issue:

Welcome to the new millennium!
A compelling reason for improving sensor technology
Shades of the ‘tricorder’
Do not overlook the impact of emissivity on temperature readings
Measuring radiant flux
Mini-robots to the rescue
Fiber optics-not just for networks anymore!
Archive
April in Control Engineering

Welcome to the new millennium!

If the last century saw the rise of process control as we know it now; what does the 21stcentury have in store for the process engineer? Is ‘smaller, smarter, faster, and cheaper’ going to be the mantra of the next 100 years? Probably not! How about ‘Internet-enabled’ and wireless technologies that apply to process control? Even though we have heard enough about that over the past 15 years, I feel sure that there is more to come. As long as companies ‘have it their way’ process-wise, process-specific control will never die. Total flexibility in system connectivity may be what the process engineer of the future is looking for.

What do you think? I welcome all comments: djohnson@cahners.com .

Back to top

A compelling reason for improving sensor technology

According to the sponsors of upcoming MessComp 2001, ‘measurement technology is the key to a more conscious use of natural resources, which are running short.’ That being said, it may be worthwhile to plan a visit to MessComp 2001, the 15thExhibition and Congress for Industrial Measurement Technology. It will be held on September 4-6, 2001 in the Rhein-Main-Hallen, Wiesbaden, Germany. Featured conference tracks will include industrial measurement technology, production measurement technology, electronic laboratory measurement technology, and environmental measurement technology. The conference is intended to serve as a platform for research and development of new sensor technologies. More information is available at www.networkgmbh.de/mce.htm .

Back to top

Shades of the ‘tricorder’

Familiar to ‘Star Trek’ fans, an essential piece of apparatus carried by crewmembers on ‘away missions’ was the trusty tricorder. This scanner could identify seemingly anything-life forms, materials, energy sources, etc.-and it was handheld. Another handheld device, the CT 4000 XRF nondestructive scanner manufactured by Edax Portable Products (Kennewick, Wa.) is doing earthbound duty. The portable x-ray fluorescence device features low detection limits that are said to make it ideal for the analysis of soils, powders, or solid waste materials. Using advanced encapsulation techniques and peltier cooling, the device can analyze up to 24 elements in less than one minute-at least here in the Alpha Quadrant. More information can be found at www.EDAX.com .

Back to top

Do not overlook the impact of emissivity on temperature readings

Do you trust the noncontact temperature measurements used in your plant’s process? According to Flow Research’s (Wakefield, Mass.) Jesse Yoder Ph.D., when asked if they take emissivity into account when making infrared measurements, 53% of users responding to the survey said no. ‘This suggests that some users are unaware of the importance of emissivity, or they assume their infrared thermometers automatically take emissivity into account when making a reading,’ Mr. Yoder reports. ‘Emissivity is important to accuracy in an infrared thermometer, and if it is not taken into account, the reading may be inaccurate,’ Yoder adds. For more from Flow Research and the Worldwide Infrared Study visit https://www.flowreseach.com .

Back to top

Measuring radiant flux

The French company Captec is said to be the world’s only supplier of heat and radiant flux sensors designed for energy measurement across a surface. Highly sensitive and miniaturizable with very low inertia, the custom-made sensor line includes conductive and radiant flux sensors, heating elements, and surface thermocouples. The heat flux sensors use thin metallic plates, which measure the energy crossing their surface. These can be used in such diverse applications as chemical reaction or phase change monitoring, wear measurement, and concrete setting monitoring.

The radiant flux sensors, unlike the flux sensors, are sensitive only to energy transfer by radiation. They can be used in air conditioning control systems to anticipate heat input from sunlight, for emissivity measurements (see item above), fire detection systems, and hot spot control. Captec also makes a version for aggressive environments such as furnaces, glassworks, and steel mills, which is a stainless steel device equipped with a water exchanger, a sapphire window, and an air gap to avoid projectiles and soot deposits. Contact Captec at www.captec.fr .

Back to top

Mini-robots to the rescue

Erratic or constricted flow in process piping can be detected through strategic placement of flowmeters and pressure sensors. However, installation of extra sensors may only be done in sections of a process where trouble might be expected and alarm conditions need to be monitored. Murphy’s Law guarantees that when leaks occur or pipes sludge up or plug it will NOT be at the site anticipated by the control engineer or system integrator. It would be a real help to process engineer to be able to get into the closed system to inspect for marginal flow conditions, either before or after the fact.

Enter the U.S. Department of Energy’s Sandia National Laboratories in Albuquerque, N.M. It’s latest creation may be the world’s smallest mini-robot. Atonsidered include a miniature camera, microphone, communication device, and chemical micro-sensor. According to Ed Heller, one of the project’s researchers, ‘it could scramble through pipes or prowl around buildings looking for chemical plumes or human movement. The robots may be capable of relayinginformation to a manned station and communication with each other. They will be able to work together in swarms, like insects.’

It may be awhile, however, before these mini-robots can actually help out the control engineer. So far, a mini-robot has maneuvered its way through a field of dimes and nickels at about 20-in./hr. It can easily sit on a nickel. Brave new world! The lab’s website is www.sandia.gov .

Back to top

Fiber optics-not just for networks anymore!

The Optical Society of America (Washington D.C.) is presenting Fiber Optic Short Courses at CLEO/QELS 2001 to be held May 6-11 at the Baltimore Convention Center, Baltimore, Md. Comprehensive educational courses and workshops involving a wide variety of topics-fiber-optic sensors are among them-from introductory to advanced levels will be featured. The annual show also features over 300 exhibitors that will be showcasing the latest technological developments and applications. For additional information, including short course schedule and descriptions, visit www.osa.org/cleo .

Back to top

Archive

As reported in the April, 1956, issue of Control Engineering’s ‘What’s New’ department about a recent Joint Computer Conference sponsored by the AIEE, IRE, and ACM in San Francisco is this comment from a ‘process industry scientist.’ ‘[There is] very little at this show that I did not see last year. Two trends are evident, however: the use of punch cards and tape to tie equipment together, and the ascendancy of digital over analog for representing various phenomena.’

Back to top

April in Control Engineering

Cover stories: Sensing

Pressure sensing

Security in software

Simulation in discrete manufacturing

Product Focus: Transmitters

Back to Basics: Linear feedback devices

Back to top