New ASTM Biodiesel Blend Measuring Method D7861 Validates Use of Portable Analysers

The recently-published ASTM method D7861 for measuring biodiesel blend ratios enables users to take full advantage of the speed, convenience and durability provided by portable infrared analysers from Wilks (USA) - a Spectro Scientific Company.

Traditional ASTM D7371 and EN 14078 methods for measuring biodiesel blends require the use of Fourier Transform Infrared (FTIR) spectrometers, equipment that is expensive and requires a level of technical knowledge to operate accurately. The new ASTM method D7861 certifies the use of portable filter-based infrared analysers, such as the Wilks InfraSpec VFA-IR Spectrometer, that are rugged, compact and much better suited for use by on-site personnel in the environment where fuels are blended. The analysers provide a fast, easy-to-use and inexpensive infrared method alternative for measuring biodiesel FAME (Fatty Acid Methyl Esters) blend percentages.

The InfraSpec VFA-IR Spectrometer is a spectral range analyser that employs a linear variable filter and a detector array covering the wavelength range of 5.4-10.8 μm (1850-925 cm-1), making it compliant with the instrument requirements of ASTM D7861. The spectrometer covers a spectral range that enables it to not only measure biodiesel in diesel, but also ethanol in gasoline and water in ethanol. The compact, portable instrument has a simplified PC interface that allows non-technical personnel to make measurements on-site at the blending terminal, as well as at manufacturing facilities or laboratories where an ASTM method is required. The analyser can measure the blend ratio in less than a minute and reads out directly in percent of biodiesel. Measurement range is 0 to 100 percent, with an accuracy of +/- 0.20 percent.

Wilks also offers the rugged, compact, fixed-filter InfraCal 2 ATR-B Biodiesel Blend Analyser. Due to its single wavelength analysis, it is does not comply with D7861; results, however, are comparable with D7371, EN 14078 and the new D7861 method. The InfraCal 2 ATR-B analyser is currently used worldwide by fuel blenders, distributors and regulators.