Shedding Light on Infrared

E-mail Ray Peacock

Infrared has been a keystone technology for industrial automation for years. And the surest way of gauging its evolution is to monitor the standards, products, and technologies that define it. The following review of developments should make it clear that change in this arena is fast and furious. Blink, and you'll fall behind.

Infrared Thermometer Standards
One of infrared temperature measurement's greatest shortcomings is its lack of national and international standards. Oh, specsmanship abounds in manufacturers' literature, but the terms used to describe an instrument's performance leave most of the technology to the imagination of the user.

Many in the field have recognized this situation, and a four-year international effort has culminated in the submittal of a draft terminology standard to the International Electrotechnical Commission (IEC) for a vote. Much like the terminology standards developed at the outset of ISO-9000, this one starts with the basics. So this installment defines all the terms used in spot infrared thermometry and temperature-measurement thermal imaging.

The draft standard, Radiation Thermometers-Part1: Specifications for Radiation Thermometers, is identified as IEC 62942-1 TS Ed1, and the commission expects to complete its vote by June. Anyone interested in seeing it become an official standard should contact the national voting committee. In the U.S., the relevant committee is the American National Standards Institute (ANSI), and a list of IEC national committee members can be found on the commission's Web site.

While standards such as IEC 62942-1 TS Ed1 indicate how mature the technology is, new products point out trends in cost and functionality.

New Products and Technologies
This year was the first time in ten years that I was unable to attend the annual ThermoSense Conference, which is part of the SPIE Defense & Security Symposium (DSS). I missed the opportunity to learn first-hand about the exciting things introduced and discussed during the presentation of papers and exposition, but thanks to the Web and SPIE's great conference coverage, I've been able to catch the important developments.

Perhaps the most exciting news from the conference was delivered by RedShift Systems, which introduced a low-cost 89 by 90 pixels imager, called the OpTIC 1080 Thermal Imaging Camera Engine. It will sell for less than $1000 in OEM quantities. The forthcoming 160 by 120 pixel-density version will be less than $1500 in quantity. And those are introductory prices.

But price isn't everything in infrared; performance and bells and whistles cost a lot. And they were there in abundance this year

For example, at the other end of the scale, FLIR introduced the mega-pixel SC8000 MWIR thermal imaging camera for scientific, R&D, and engineering applications. It is unparalleled with a 1024 by 1024 focal plane array (FPA) detector, and it also features gigabit Ethernet and USB interfaces for maximum flexibility and performance.

IRCAM GmbH, from Erlangen, Germany, introduced the Geminis 110k ML, a dual-band infrared camera for versatile use in research and industry. It permits synchronous, pixel-registered acquisition in the mid-wavelength (MWIR) and long-wavelength (LWIR) ranges. By direct comparison of MWIR and LWIR images, entirely new applications in IR imaging become possible, such as characterization of materials, analysis of smoke and gases, identification of reflections, and precise noncontact measurement of temperatures.

Not to be outdone, Princeton Lightwave introduced the dual-band Visible-IR camera, a one-dimensional linescan camera that uses two independent sensors. The sensing devices are optically coupled to allow simultaneous imaging in both visible (400–900 nm) and infrared (1100–1700 nm) wavelengths. Princeton Lightwave says the performance and reliability of the camera make it well suited for industrial imaging applications.

If suitably calibrated, this would mean a Web or wide product operation, such as hot rolling in steel and other metals industries, could have temperature and visual maps of their products made simultaneously. Combine this capability with smart machine-vision algorithms, and you would have a smart defect locator. In flat glass, rubber, textile, paper, and other processing lines, there would be additional exciting opportunities to identify both product and process problems with one package.

Speaking of paper, Analytical Spectral Devices Inc., Boulder, CO, has signed a strategic alliance agreement with Paprican, the Pulp and Paper Research Institute of Canada, to develop the pulp and paper industry's first application of near-infrared technology to measure pulp brightness and lignin content. The new analyzers promise to optimize lab and industrial measurements of these parameters, leading to better control of the manufacturing process with reduced costs and better environmental performance.

NEC San-ei Instruments, distributed in the U.S. by Mikron Infrared introduced a new high-quality, 60 fps thermal imager that features a visual camera built into the IR lens on all standard, telephoto, and wide-angle lenses. This provides minimal parallax and the same magnification for the visible as the infrared. Another dual waveband unit with a different purpose provides both the thermographer and the analyst clear visible images that register precisely on the object being monitored.

Thermoteknix Systems Ltd., of the U.K., introduced the new MIRICLE 110KS camera, which raises the technology and sensor stability bar with the world's "first" FPA thermal imaging camera with shutterless technology. By eliminating the shutter and associated motor, gears, and control, these cameras are smaller and lighter and consume less power, a major benefit to all portable and size-critical applications. In critical situations, such as object tracking and online machine vision applications, the complete obstruction to vision produced by a shutter can be at least, inconvenient, and at worst, costly.

OPGAL Optronic Industries Ltd., of Israel, another supplier of infrared cameras, software, and complete camera systems, now offers the palm-size EYE-R640 thermal imager at different levels of integration. Among them are the engine and the camera levels, which make the perfect solution for OEM customers and partners in the defense and security markets. This high-performance infrared engine is a small-size (42 mm by 43 mm by 63 mm) and light (under 180 grams) thermal imaging device.

For spectral imaging applications, Solid State Scientific's hyperspectral imaging sensors combine the effectiveness of up to 74 narrow band images of the same scene with the efficiency of a high-throughput camera. The multiple spectral images—or hyperspectral data cube—form the input to standard spectral processing techniques, such as those used for image segmentation, material identification, and object detection.

Another example of optical innovation is the VideometerLab system from Videometer. This company has implemented high-resolution multispectral images at wavelengths from 230 to 1050 nm (near UV to near IR). Their system is a color and texture measurement vision system, which is based on a high-intensity integrating-sphere illumination featuring light-emitting diodes together with a high-resolution video camera. The well-defined and diffuse illumination of the optically closed scene enhances the true color as well as color variation of samples. The technology has uses in industries such as biotechnology, food, pharmaceutical, and graphics.

This is by no means a comprehensive list of new products that debuted at the ThermoSense Conference. But I do consider them trailblazers of the industry.

Thanks for reading. See you next month.