August 2007

New Snap-In Air Temperature Sensor Features Good Thermal Response

Spectrum Sensors and Controls, Inc. has released a snap-in temperature sensor with a special clip design that allows the sensor to more accurately monitor air temperature within an enclosure. Until now, the most common way to accomplish this was by surface mounting the temperature sensor directly to sheet metal, often causing the sensor to give an inaccurate temperature reading from the sheet metal rather than the air in the enclosure.

Now, Spectrum’s new snap-in temperature sensor’s fast response thermistor element is integrated into a potted metal housing that can be securely snapped into a 0.30 inch diameter pre-drilled hole in sheet metal. This keeps the sensor off the sheet metal while the plastic molded body with strain relief thermally separates the assembly from the environment on the backside.

Spectrum’s snap-in air temperature sensor features standard resistance values ranging from 2,252 to 10,000 Ω at 25°C with a variety of thermistor values and curves, snaps into 14 to 18 gauge sheet metal and comes standard with 10 feet AWG#22, PVC insulated leads.

Spectrum’s snap-in air temperature sensors are priced at $5.25 each at 1,000 pieces.

Nanostructured Thin Film TEG Harvests and Converts Waste Heat into Electricity

Nextreme, Inc. has introduced a miniature, thin film thermoelectric generator (TEG) that converts heat directly into electricity. Suited for waste heat conversion applications, the solid state TEG delivers power generation densities (>3 W/cm2) in excess of those achieved using bulk materials and is manufactured to provide power in a form factor that can be as much as 20 times thinner than bulk material alternatives. This opens up waste heat energy conversion applications for the Nextreme technology as well as remote power applications. Manufactured using semiconductor fabrication techniques, the TEG is scalable, cost-effective and can be utilized in a broad range of markets and applications including automotive, military and aerospace, thermal batteries, medical implants and wireless sensor networks.

“In environments where a lot of heat is available we have demonstrated power levels of up to 300 mW with devices that are not much bigger than a piece of confetti,” said Dr. Seri Lee, Nextreme chief technology officer. “And in low grade thermal environments, we have demonstrated micro-watts of power – enough thermal energy conversion to power remote sensors and other distributed devices.”

Nextreme’s TEG has demonstrated output power levels of >100 mW at ∆T of 70°K and >300 mW at ∆T of 120°K. With modules measuring 3.5 mm by 3.5 mm, the TEG has corresponding output power densities of ~ 1 – 3W/cm2.

Nextreme’s TEG devices generate electricity via the Seebeck Effect, where electricity is produced from a temperature differential applied across the device. The temperature difference (∆T) between the hot (Th) and the cold (Tc) sources leads to a difference in the Fermi energy (∆EF) across the thermoelectric material yielding a potential difference, which drives a current.

Cedip Infrared Systems Releases Third-Generation Thermal Camera

Raytek, a provider of infrared thermometry, has introduced the Raytek XR infrared (IR) thermometer. Designed to provide continuous temperature monitoring in a broad range of manufacturing processes, this improved sensor is a rugged, NEMA 4 sealed single-piece system with the flexibility to handle numerous applications.

The Raytek XR infrared thermometer combines a variety of features, including multiple extended temperature ranges, precision temperature resolution, RS-485 outputs and a versatile electronics platform.

The sensor provides a flexible, user-defined analog output that can be matched with almost any existing control system. This feature also eliminates the need for expensive A/D conversion or non-standard A/D input cards. An intuitive local user interface simplifies system setup and configuration and adds troubleshooting capabilities.

The Raytek XR infrared thermometers, with multiple measurement ranges, utilize identical, configurable installation hardware and application software. This approach reduces installation time, training and documentation requirements and spare parts costs.

When Biomarine, Inc., a division of Neutronics, Inc., was designing the housing for its revolutionary new BioPak 240R Self Contained Breathing Apparatus (SCBA), it turned to Premix Thermoplastics, Inc. for help in developing a thermoplastic compound that would meet the unit’s demanding requirements for withstanding, even the most rugged use while providing protection against radio interference. 

Certified by NIOSH/MSHA, EN136/EN137/EN145 and the Chinese Mining Authority, the new four-hour BioPak 240R is a long duration rebreather. With its 6 liter tidal volume, disposable solid CO 2 scrubbers, and quick-change coolant, the 240R provides advancement in closed circuit, self-contained breathing apparatus technology. Overall user safety and comfort has also been increased over standard SCBA with an ergonomic design and advanced status/warning systems. The BioPak 240R rebreather is designed for use in mine and tunnel rescue, industrial accidents, Hazmat clean-up, search and rescue and military or homeland security actions.

For the housing of the BioPak 240R, Biomarine needed a material that’s properties included the ability to handle impact requirements and withstand continuous temperatures of 190°F (88°C) without deforming. In addition, the material had to withstand 15 seconds of direct flame without burning or showing after glow, or flame after the flame is removed.   It also needed to have a surface resistivity of less than 1-e9 ohms in order to control static buildup and charges.

Using a matrix approach to developing a customized compound for the housing, Premix engineers considered a number of options. Initially, they thought PRE-ELEC ESD 14-000 would be an excellent choice due its high impact resistance, heat deflection and color ability.  However, they quickly ruled it out because the flame test showed that the inherently dissipative polymer (IDP) in this PC alloy would release some of its chemically bound water molecules and cause blistering on the surface of the BioPak which was unacceptable.

Another option considered was PRE-ELEC 14-000, a carbon black polycarbonate compound that met all the physical, thermal and electrical requirements. However, this was ruled out because Biomarine wanted to manufacture BioPak with some color in it.

Next on the list for consideration was PRE-ELEC 14-031, which could be easily colored gray for the housing but its impact resistance was too low.  Even with impact modification, PRE-ELEC 14-031 would not meet the requirements for the application.

This left only one option, PRE-ELEC 14-040, a stainless steel fiber polycarbonate, but even this compound needed impact modification to meet the impact properties. After strenuous testing, the impact-modified compound, PRE-ELEC 14-040-HI, became the product of choice. Premix supplies it in black, gray and yellow. 

The ability to offer so many conductive and static dissipative compounds allows Premix to utilize this type of matrix approach when customizing compounds.  By tabulating the requirements versus the abilities of its individual compounds, it is possible to develop special compounds very quickly. It took less than 12 weeks to have a material qualified for the housing of Biomarine’s SCBA.

Knowledge Center to Launch in September  

The THERMAL News Web site, www.ThermalNews.com is gaining a new resource that will make navigation easier. The Online Knowledge Center, a one-stop resource section packed with information about the thermal industry, will be launched at the beginning of September. This new section of the Web site will feature White Papers, book listings, Application Profiles, information about upcoming events such as Conferences, Webinars and Training Courses and much more.

Do you have White Papers and information about Webinars and training courses you would like to see listed in the Knowledge Center? If so, please e-mail Joanna Larez at joannal@infowebcom.com.

The editors at THERMAL News are interested in your input! The Web site now features a Survey of the Month section on our homepage. Please visit the Web site to view this new portion on the homepage. Also, please let us know what questions you would like to see featured as the Survey of the Month. Visit the Web site for responses to previous questions.

Responses will help us as we continue to develop editorial content for the publication.

The current question is: In your opinion, what are the most exciting areas of R&D today? http://www.thermalnews.com/

We look forward to receiving your input!

Laird Technologies, a company focused on critical components and systems for advanced electronics and wireless products, has established a Corporate Research Laboratory in Bangalore, India.

The focus of the new laboratory will be in development of novel materials and for use in electronic components and systems. A broad range of technical specialists, including physicists, chemists and material scientists will be recruited in coming months to staff the laboratory. These technical specialists will augment Laird Technologies’ global engineering and technology staff of more than 400.

The facility is located in the International Technology Park (ITPL) in Bangalore. Dr. B. K. Chandrasekhar has been appointed Director of the Bangalore Laboratory, coming to Laird Technologies from General Electric where he held a similar position. The Laird Technologies laboratory shares Bangalore as a home along with many major technology companies and will serve as the technical hub for the company as it expands in India.

Among the ATS cooling solutions offered through the Digi-Key catalogue are maxiFlow flared fin, high-performance heat sinks, along with straight-fin and cross-cut extruded sinks. Other heat sinks are available for cooling Freescale MPC 8641D dual-core and LGA processors, a wide variety of ASICs, and for linear LED lighting applications. Every heat sink is provided with performance and physical specification.

Digi-Key customers can also order the ATS maxiGrip system for safe and secure heat sink attachment to flip chips, BGAs, and other hot on the PCB components. The maxiGRIP system features a plastic frame clip that snaps securely around a component’s perimeter. A stainless steel spring clip runs though the heat sink’s fin field and fastens securely to the plastic frame. As a result, the sink is mounted securely to the component with steady, even pressure. ATS’ maxiGrip assemblies are available in a wide-range of component sizes from 17 mm by 17 mm to 45 mm by 45 mm.

Adding the HCS expands the Global Preferred Vendor Agreement, which previously covered Moore Industries’ HIM HART Loop Monitor. Under the agreement, Yokogawa will sell application solutions that include its HART-based instruments and Moore Industries’ HART interface modules. Moore Industries will provide sales, marketing and application support to Yokogawa’s worldwide distribution channels.

The Hart Concentrator System allows users to extract data from multiple Yokogawa Hart devices. Up to 16 HART devices, such as any combination of Yokogawa’s RotaMass 3 Series Coriolis Mass Flowmeter, EJX910A Hart Multivariable Transmitter and digital Yewflo Hart Multivariable Vortex Flowmeter, can be connected to a single HCS. This allows users, who may not have HART capability in their control systems, to acquire all digital process and diagnostic data from Yokogawa’s field instruments and send it via Modbus to a control system.

Installed transparently across each transmitter’s 4 to 20 mA Hart loop, the HCS extracts all of a smart transmitter’s Hart data by reading the Hart digital data that “rides” on the loop wires. For example, when used with Yokogawa’s RotaMass 3 Series Coriolis Mass Flowmeter, the HCS will extract mass flow, density, temperature, volume flow, concentration, net flow and diagnostics and send it via Modbus for direct input to a Modbus-based control system. 

Solar Power Generation Benefits from Dow Performance Fluid Chemistry

Dowtherm, a Heat Transfer Fluid from The Dow Chemical Company, is helping a large solar power plant, Nevada Solar One, convert sunlight into electricity.

Dow Performance Fluids recently delivered several million dollars worth of the fluid to Solar One’s Nevada desert location. The large quantity of material will play a critical role in the operation and generation of renewable electricity at the new solar power plant.

Heat Transfer Fluids & Solar Power

Solar energy collectors generate a great deal of heat. In the parabolic collector system, the role of the heat transfer fluid is actually to collect this heat energy and transmit it to the power generating equipment where the steam to drive the electricity generating turbines is made. Dowtherm A Fluid is suited for systems that use liquid phase or vapor phase heating. The material is a mixture of two compounds: biphenyl and diphenyl oxide. Both substances possess the high-temperature thermal stability needed to collect and transport heat from the sun to the power generating station.

Temperature Controlled Transport

In addition to Dow’s capacity to supply Nevada Solar One with material in a short amount of time, the company also provided the logistical support needed to transport the Dowtherm A Fluid. A total of 72 ISO-containers with fluid heated to 130 degrees Fahrenheit were sent to the site in five days.

“There are very few companies that have the ability to fulfill a shipment of this size while also meeting the necessary requirements,” said Steven Stanley Ph.D., global business director for Dow Performance Fluids. “There are other, similar solar opportunities coming on line in Spain and Mexico. With global supply capabilities, we believe Dow is well positioned to perform in those countries just as we have in Nevada.” 

Solar One Harnesses the Sun

Nevada Solar One uses parabolic mirror troughs as thermal solar concentrators to heat tubes of liquid Dowtherm A. The heated material generates steam to power electric turbines. These solar receivers are specially coated glass and steel tubes. About 19,300 of these four-meter-long tubes are being used to generate 64 mega watts of electricity, which is enough electricity to power about 45,000 average homes for a year. Plants like Solar One are suited for areas like the Southwestern US, a region that uses a significant amount of electricity to run air conditioning. With the land and sun resources available in places like Nevada, and state regulations mandating that at least 5 percent of electric power come from solar energy by 2015, it is likely that even more plants like Solar One will be built.

August

19-23 American Chemical Society 234th National Meeting and Exposition, Boston, Mass.

22-24 Radiant Panel Association Annual Conference and Semi-Annual Radiant Exposition, Hartford, Conn.

September

11-13 The Predictive Maintenance Technology Conference and Expo, Las Vegas, Nev.

16-19 Thermoforming Conference 2007, Cincinnati, Ohio

17-19 ASM Heat Treating Society Conference and Exposition, Detroit, Mich.

24-26 Insulating Concrete Form Association Fall Meeting and Expo 2007, St. Louis, Mo.

25-27 National Manufacturing Week, Rosemont, Ill.

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