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Li Y.,Australian National Measurement Institute
CPEM Digest (Conference on Precision Electromagnetic Measurements) | Year: 2010

Precision DC voltage dividers with ratings up to 1000 kV have been built using the 150 kV resistor module developed at the National Measurement Institute, Australia (NMIA). The structure of the 150 kV resistor module and the measurement techniques for evaluating its performance are described. The method for evaluating voltage ratio errors at voltages up to 1000 kV is discussed. It is shown that a ratio error of less than 5 μV/V at 150 kV and less than 100 μV/V at 1000 kV can be achieved. © 2010 IEEE. Source


Ballico M.,Australian National Measurement Institute
International Journal of Thermophysics | Year: 2011

The replacement of ITS-90 temperature measurements by direct thermodynamic temperature measurements based on radiometric techniques in the temperature range above 1000°C has been proposed by many national measurement laboratories. This article reports on work at NMIA to develop a simple and robust traceability scheme for thermodynamic temperature, based on the use of photometers and a Thermogage furnace with a graphite tube element modified to improve its temperature uniformity and emissivity. A simple luminance meter was constructed using a commercial photometer and pairs of precision apertures to view the rear of the blackbody cavity. This photometer was calibrated against NMIA reference illuminance lamps, and relative spectral responsivity measurements were used to determine the color-temperature correction between the lamps and the Thermogage blackbody. Thermodynamic temperature determinations made using various combinations of apertures and photometers showed a range of less than 0.2°C at 1700°C, consistent with the calculated uncertainty of 0.29°C (k = 2). ITS-90 measurements made by NMIA's LP5 and HTSP primary radiation thermometers with an uncertainty of 0.16°C (k = 2), are consistent with the thermodynamic measurements. It is suggested that routine thermodynamic temperature determinations can now be made with an effort comparable to that required to realize the ITS-90 above 1000°C. © 2011 Springer Science+Business Media, LLC. Source


Kazlauskas R.,Australian National Measurement Institute
Handbook of Experimental Pharmacology | Year: 2010

Anabolic steroids have been studied for over 50 years and during that time numerous compounds with a variety of functional groups have been produced and many have been published. Of these only a small number have been introduced to the pharmaceutical market. WADA has continued the work begun by the IOC banning the use of these agents within sport as performance enhancing substances. Athletes, however, continue to use these anabolic steroids but tighter testing and the introduction of unannounced sample collection has made this form of cheating harder. In order to try to evade detection, athletes who continue to dope are having to resort to the use of a far more dangerous form of drug - the designer steroid. These steroids are manufactured to closely resemble existing known compounds, but with sufficient chemical diversity to ensure that their detection by the WADA accredited laboratories is more difficult. A worrying feature of the use of these compounds is that no data is available to evaluate either the efficacy or the safety of these substances. Many such drugs are now being made in clandestine ways (as demonstrated by the recent BALCO case) and then passed on to athletes who become the guinea pigs determining the potential of the substances as doping agents. Methods for the detection of these new compounds are being developed using emerging techniques such as gas chromatography or liquid chromatography attached to a variety of mass spectrometry instruments. This technology as well as vigilance by laboratories and enforcement agencies can all help in early detection of designer steroids being used for doping. © 2009 Springer-Verlag Berlin Heidelberg. Source


Koeberl M.,James Cook University | Clarke D.,Australian National Measurement Institute | Lopata A.L.,James Cook University
Journal of Proteome Research | Year: 2014

Food allergies are increasing worldwide and becoming a public health concern. Food legislation requires detailed declarations of potential allergens in food products and therefore an increased capability to analyze for the presence of food allergens. Currently, antibody-based methods are mainly utilized to quantify allergens; however, these methods have several disadvantages. Recently, mass spectrometry (MS) techniques have been developed and applied to food allergen analysis. At present, 46 allergens from 11 different food sources have been characterized using different MS approaches and some specific signature peptides have been published. However, quantification of allergens using MS is not routinely employed. This review compares the different aspects of food allergen quantification using advanced MS techniques including multiple reaction monitoring. The latter provides low limits of quantification for multiple allergens in simple or complex food matrices, while being robust and reproducible. This review provides an overview of current approaches to analyze food allergens, with specific focus on MS systems and applications. © 2014 American Chemical Society. Source


Georgakopoulos D.,Australian National Measurement Institute
IEEE Transactions on Instrumentation and Measurement | Year: 2011

Providing the traceability of alternating-current (ac) voltage measurements by means of a stepwise-approximated sine wave (SASW) produced by a programmable Josephson voltage standard (PJVS) is an attractive alternative to the conventional ac voltage standards based on thermal voltage converters, because a programmable Josephson standard has a calculable output voltage that does not drift with time. This paper investigates two aspects of uncertainties in the measurement of ac voltage using a sine wave generated by a PJVS with a lock-in amplifier as a null detector. First, the uncertainty introduced by transitions between successive voltage levels of the SASW on the fundamental and root-mean-square values is examined. Second, the lock-in amplifier response to the harmonics of this synthesized sine wave is discussed. Experimental evaluation shows that harmonics that are not rejected by the lock-in amplifier can cause a systematic error when measuring the ac-direct-current difference of a thermal converter with the synthesized sine wave from 0.5 to 3.0 μV/V, depending on the number of samples per period of the SASW. Furthermore, it is shown that this error can be reduced to 0.3 μV/V by calibrating the lock-in amplifier using a distorted signal having a similar harmonic content to the synthesized sine wave. © 2006 IEEE. Source

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