Following on from IM’s report on ever more stringent diesel particulate emission standards in the February issue, Donaldson, a leading, worldwide manufacturer of filtration systems and parts, has recognised Phillip Johnson, Director, Liquid Filtration, New Business Development at Donaldson for his work on Fuel Filtration Reality Check, a study that predicts by 2010 that diesel injection systems will require much higher efficiency filtration below 5µm and need to be significantly cleaner than the technology allows today. Johnson delivered the study at the 9th International Filtration Conference in November 2008 hosted by Southwest Research Institute® and was awarded the Peter Herman Award for Outstanding Technical Presentation. In the study, Johnson discusses how engine design and available fuel types have changed significantly in the past 20 years based on legislation, regulation and rapidly escalating oil prices. Yet, fuel specifications and fuel filtration have seen little change. He concludes that providing clean fuel throughout the distribution channel will become a prerequisite for diesel engine applications.Johnson also outlines the filtration industry’s need for new standards and new ‘systems’ technologies to measure fine particulate and other contaminants. “Stakeholders, such as fuel companies, distributors, suppliers, engine manufacturers and filter companies can no longer work in siloed environments within the supply chain to meet filtration requirements for engine manufacturers,” said Johnson. “Filtration solutions will need to take a ‘systems’ approach where we work in collaboration to provide the highest level of customer satisfaction.”To read “Fuel Filtration Reality Check” in its entirety, visit http://www.donaldson.com/en/engine/support/datalibrary/063416.pdf or request a copy at (952) 887-3034.
An intercomparison of zenith-sky UV-visible spectrometers was held at Camborne, UK, for 2 weeks in September 1994. Eleven instruments participated, from nine different European institutes which were involved with the Second European Stratospheric Arctic and Mid-latitude Experiment (SESAME) campaign. Four instruments were of the Systeme d’Analyse d’Observations Zénithales (SAOZ) type, while the rest were particular to the institutes involved. The results showed that the SAOZ instruments were consistent to within 3% (10 DU) for ozone and 5% for NO2. For ozone the results from these instruments agreed well with total ozone measurements by Dobson and Brewer spectrophotometers and integrated ozonesondes when the air mass factors for the SAOZ were calculated using the ozonesonde profiles. Differences of up to 10% in ozone and 30% in NO2 were found between different instruments. In some cases these differences are attributable to the different absorption cross sections used in the analysis of the spectra, but other discrepancies remain to be investigated. A prominent source of error identified in the campaign was uncertainty in the derivation of the amount of absorber in the reference spectrum, which can contribute an error of up to 3% (10 DU) in ozone and 1.5×1014 molecules cm−2 in NO2.