IRWeb INFO

Contents [FREE] - pp.127-128
Thermographic analysis of phacoemulsification based cataract surgery procedures
B.INNOCENTI, A.CORVI, R.MENCUCCI pp.129-140

Scale reduction in modeling landmine detection by IR thermography
A.MUSCIO, L.TAROZZI, M.CORTICELLI - pp.141-154

Improved ultrasound activated thermography using frequency analysis
A.GLEITER, C.SPIESSBERGER, G.BUSSE- pp.155-164

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{Image Courtesy Williamson Corporation}
From the Williamson IR website page on Applications of Dual Wavelength infrared thermometers:

“One of the greatest advantages of a dual-wavelength infrared thermometer is that the target can be smaller than the optical resolution of the sensor. This feature is particularly appropriate when viewing past an optical obstruction or when viewing a small or wandering target such as a thin wire…”

“For this application, the dual wavelength sensors are able to provide a relatively large target area of 0.5in diameter while measuring the significantly smaller wire. Using a dual-wavelength sensor it is possible to measure a wire that is less than 0.001in diameter and with a wander from side to side of as much as 0.2in.”

(ED NOTE: This IR thermometer type, dual wavelength or dual waveband wherein the dual signals are ratioed are sensitive to the ratio of the spectral emissivities in the two spectral wavelength bands and are only insensitive to emissivity changes if the emissivity ratio does not change.

In such a situation the object of measurement is called a gray body, and it is relatively rare except for some of the Iron Oxides that are found on Iron & Steel within the wavelength regions used by many commercial relatively “short wavelength”, infrared thermometers, eg: 0.7 to 2.5 micrometers.)

Concord,MA, USA — As seen on the Williamson IR website:

“Single wavelength infrared thermometers filtered in the short wavelength region of 2.0 to 2.5 microns offer good performance when measuring low emissivity materials at low temperatures.”

“The accuracy improvement associated with the shorter wavelength sensor is shown in the figure below. The shorter wavelength sensor shows an improvement in measurement from about 18°F (10°C) to about 5°F (2.8°C) when measuring a 220°F (104°C) target with a 10% variation in emissivity. This alone does not explain the total improvement in accuracy achieved by the component supplier. The short wavelength measurement also benefits from the fact that most metals have a higher emissivity value at the shorter wavelength. Therefore, considering these two benefits the shorter wavelength sensor offers as much as ten times more accurate readings than is a long wavelength sensor.”

{Image: Courtesy Williamson Corporation}

Read the rest of an actual case story at www.williamsonir.com/page.php/id/233

ED NOTE: The terms “Short Wavelength” , “low emissivity” and “low temperature” are relative, of course and here they are used in the context of a measurement in the 150 to 1000°F temperature region of unoxidized metal surfaces.

True wafer temperature measurements in Molecular Beam Epitaxy, or MBE, is an applications story (Application Note 18) from LayTec GmbH in Germany about the benefits of this technology in semiconductor processing, especially for GaAs (Gallium Arsenide) and InP (Indium Phosphide), two materials that are opaque at the wavelength region of interest in the Near Infrared (NIR), 950 nm.

The lead in to the applications note reads as follows:

“LayTec’s in-situ sensors are state-of-the-art in-situ growth monitors for basic growth studies, process development, process transfer and for enhancing run-to-run reproducibility in production environment. These sensors are offered for a variety of growth systems in MBE, MOVCD and other growth techniques. All sensors are available with LayTec ?s True Temperature measurement mode based on emissivity corrected pyrometry: EpiTT, EpiR TT and EpiRAS TT“.

You can download a copy of the entire note: “True wafer temperature measurements in MBE “- CLICK HERE - PDF - 122 Kb

A downloadable PDF FIle from Mikron Infrared describes the use of IR Thermometers in manufacturing operations using thermoformed plastic sheet materials.

Thermoforming Applications: Thermoforming Temperature Measurement

The Thermoforming Application

Thermoforming is the process of using heating elements and/or cooling elements to mold or shape
some type of material. Typically this material will be a type of plastic.

The process follows a path from extrusion to molding. Most thermoforming companies will use extrusion machines to extrude the plastic, which then will be pulled into an oven and heated until it reaches a certain temperature.

Once this temperature has been obtained the plastic is moved out of the oven into a cooling and molding zone. Usually the machine runs on a timer so the temperature of the plastic varies and is inconsistent within the oven.

The plastic is molded and cooled either by water-cooling or air-cooling. Most applications use water-cooling either sprayed onto the plastic or pushed through the metal mold.

Finally, the plastic is moved to a cutting zone where the shapes are cut out of the plastic. This can be done either manually or automatically as well.

This application has a couple of different sections that are ideal for infrared pyrometers and imaging.
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Large Area Calibrators with Radiometric Calibration Traceability From -15 °C to 500 °C!

American Flats UT, USA — The new blackbody calibrators being offered by Hart Scientific are a breath of fresh air.

They come with radiometric calibration traceability built-in and the sales web page on the Hart Scientific website is exceptionally informative.

So, too are the online and free downloadable PDF files of the Users Manual (in 7 additional languages), the Technical Manuals and an Applications Note entitled “IR Calibration 101″!

Not only are they exceptionally complete and well-written, in our opinion, they set a new benchmark for their competitors, Ametek-Land and Mikron Infrared in the industrial and scientific blackbody arena.

It looks like Fluke has really done its homework and executed a well-reasoned product development plan.

Kudos to the people at Hart Scientific and Fluke!

K. Irani, one of the founders of Mikron Infrared and well-known in Infrared circles as one of the driving force behind Mikron’s in-depth product line of Infrared Calibration products, has retired from his active tasks.

He is now offering consulting services through a new organization Infrared Technologies, Inc and their website “Infrared Technology” (201-264-1900 phone), Offering:

“Consulting services for non-contact temperature measurement,
infrared thermal imaging, and blackbody calibration sources”

Among the interesting things to be found on this website are a series of industrial applications stories on uses of Infrared thermometers and Thermal Imagers.

Here is an example of one of them: A Coal-fired power plant movie that depicts accumulation of ash on wall tubes.

Click on the image to launch movie.

To learn more about Infrared Technology Inc., please contact them directly.