News
Spring 2010 - 12/02/2010
Welcome to the Spring 2010 Specac Newsletter.
We're sending you our regular bulletin to keep you up to date with the latest news on the new products that we're developing and some special offers that you can take advantage of. We're also giving you a more in depth look at one of the many products we offer as well as keeping you informed of trade shows we'll be attending.
Specac, the World's leading spectroscopic accessory manufacturer, produces the industry's widest range of Lab IR sampling accessories for solids, liquids & gases. Our fully integrated sampling solutions work at temperatures from -190°C to 800°C, at pressures from vacuum to 6000 psi and under corrosive conditions that leave other manufacturers bewildered.
International blue-chip enterprises, OEMs and research institutions depend on Specac, you can too. So whatever your application you can be sure we already have the ideal sampling solution.
Soon we will be launching our SpectroElectroChemical Transmission Cell which is based on an OTTLE (Optically Transparent Thin Layer Electrode) concept. SpectroElectroChemical Spectroscopy allows the application of an electric field to the sample whilst recording spectroscopic absorption features.
This has particular application for monitoring redox-coupled reactions, to allow in-situ spectroscopic analysis of electro-generated intermediates or products.
We are currently redesigning our 40 ton press offering, which will be launched in the middle of the year, we will be announcing more details nearer the time. Keep an eye out for more information comming soon.
The VT Cell is the ideal accessory for the transmission study of liquid or solid samples through a temperature range of -190°C to 250°C.
The Variable Temperature Cell consists of a vacuum jacket with standard NaCl windows which contains a refrigerant dewar/cell holder assembly.
Sample cells are inserted into the heating block part of the dewar/cell holder and the unit is operated within a vacuum environment maintained by the outer jacket. Using a combination of refrigerant and control from the cell block heaters any temperature from -190°C to 250°C can be achieved. Choice of window materials allows for the use of ths accessory in UV, visible and IR regions.
The Variable Temperature Cell is supplied with a high stability controler with an RS232 interface for independant control using a personal computer.
Special versions of this cell have been designed for use in Raman and Fluorescence applications. These cells use four ports and samples are contained in cuvettes or bulbs.
Analysis of the Thermal Runaway Properties of Germanium using the Variable Temperature Cell.
The suitability of an infrared material for a particular application depends on its useful wavelength range and transmission characteristics including surface losses, inertness, thermal conductivity, expansion coefficient, hardness and susceptibility to shock.
Germanium is a very versatile optical material used in thermal imaging systems, optical design applications and infrared analysis. It is non-hygroscopic, chemically resistant to many solvents, has a excellent surface hardness and good mechnical strength. It also has a wide useful transmission range of 2-12 microns. Having a high refractive index of 4 results in high reflection losses though these may be greatly reduced by employing antireflection coatings. However, its high refactive index makes it a material of interest for use in attenuated total reflection (ATR) spectroscopy.
The transmission of some infrared materials is known to reduce with temperature, and Germanium is one of the materials known to exhibit such thermal runaway properties. Consequently, it is essential to know the relationship between transmission and temperature in applications involving Germanium.
The spectra shown above were recorded on a modern FTIR spectrophotometer, conditions set at 8cm-1 resolution, 8 scans. A monocrystalline Germanium 2mm thick, n-type and 5-40 ohm cm resistivity was used. The recorded data are indicative that thermal runaway properties of Germanium become severe at about 150°C. This effect is due to the generation of free electrons at elevated tem[eratures with proportional increase in free electron absorption. The n-type and/or low resistivity Germanium exhibits slightly less thermal runaway properties than the p-type and/or high resistivity Germanium. The bands observed beyond 11.7m (860cm-1) are due to overtones of the fundamental phonon absorptions and have been proved to be independent of carrier concentration.
For heated applications such as monitoring heated process flow streams by ATR or heated gas analysis, Germanium is a suitable material only up to 150°C and wavelength of 11microns. Beyond this temperature transmission reduces significantly and Germanium is not recommended for infrared transmission studies. The useful transmission range also reduces with increased temperature, becoming completely opaque above 7m (1430 cm-1) at 250°C. The study confirms why Germanium is restricted to low power CO2 laser applications (typically 100 watts c.w.) and is not used as an aerodynamic transmitting component where heat is likely to be generated.
The Specac Variable Temperature Cell (VT Cell) 21525, with controller as shown above, was used in this study. The VT Cell operates between -190°C and 250°C and has been designed to give high precision variable temperature in routine or research use. The accessory may be installed in most modern IR/FTIR spectrophotometers, requiring no alignment.
Acknowledgement: the above study was carried out by Specac Ltd.
We would like to thank all those who took part in our recent servey. Our congratulations go to Carol Edwards from Imperial College (below), who was drawn out of the hat and won herself an iPod Touch!
Specac exhibited at the BCEIA in Beijing at the end of November as part of the British pavilion organised by GMBICA. This was the first time that Specac has exhibited in China and we were delighted at the very high level of interest in Specac's range of FTIR accessories, especiall from spectrometer manufacturers, Specac exhibited a wide variety of our FTIR accessories on the stand which visitors found very helpful to understand their operation and quality.
The BCEIA was a great success for Specac with significant interest especially in our advanced research accessories such as the High Temperature High Pressure Cell and High Temperature GoldenGate Diamond ATR.
David Smith, Managing Director of Specac, commented "It is well known that China is an expanding market and there is tremendous opportunity for Specac to significantly increase our sales of FTIR accessories there. The BCEIA trade show has provided a great foundation for Specac and we will be working hard to strengthen the relationships we established in Beijing".
Pittcon is the world's annual premier Conference and Exposition on laboratory science. It is organized by The Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, a Pennsylvnia not-for-profit educational corporation. Pittcon attracts nearly 20,000 attendees from industry, academia and government from 90 countries worldwide.
We will be there with a wide range of our products on display and our technical experts and sales team there for you to speak to. We will be on stand 1221, please come and see us.
Munich in Germany will host Analytica 2010 and for the first time we will have our own stand. Here you will be able to see a selection of our products amd meet members of our technical support and sales teams. We look forward ro seeing you on stand A2.147.
A full list of events that we will be attending is available on our website, we will be keeping this up to date as more information becomes available.
Our technical experts are always are always willing to help our customers with their technical queries and issues. The team can be contacted via the "Technical Support" section of our website or by email: TechSupport@specac.co.uk
