ASTM International standard D 1555, Test Method for Calculation of Volume and Weight of Industrial Aromatic Hydrocarbons and Cyclohexane, and its metric equivalent, D 1555M, have been revised by Committee D16 on Aromatic Hydrocarbons and Related Chemicals. The revision affects the basis for correcting volume from any temperature to 60 F (or 15 C using D 1555M), as well as calculating the weight of product given the volume at a specific temperature.
Test Methods D 1555 and D 1555M are frequently used to calculate the mass of a quantity of material from the measured volume and temperature. The affected chemicals are: cyclohexane, benzene, toluene, mixed xylenes, styrene, ortho-xylene, meta-xylene, para-xylene, cumene, ethylbenzene and aromatic hydrocarbon boiling point ranges of 300 to 350 F and 350 to 400 F. Given the volume of the markets that this standard may affect, great care was taken to ensure technical accuracy.
The purpose of the revision was to make the standard more technically correct and adapt it to modern use. The most significant change is replacement of the volume correction factor table with equations that allow calculation of the VCFs in place of a manual interpolation from the original tables. This change will improve the precision of the procedure and allow the procedure to be integrated with automated techniques more easily. The VCFs, although now five places past the decimal, are no more than +/- 0.0001 different than the previous four-place VCFs, or +/- 0.01 percent. In addition, the densities at standard temperature for the pure materials are derived from densities furnished by NSRDS-NIST 75-121, published in 2001 (National Standard Reference Data Series - National Institute of Standards and Technology). These values are considered more accurate than base densities determined in 1971.
For further technical information, contact Larry A. Montano, Chevron Phillips Chemical Co., the Woodlands, Texas (phone: 832/813-4431; firstname.lastname@example.org). Committee D16 meets June 22-24, in Pittsburgh, Pa. For membership or meeting details, contact Diane Rehiel, ASTM International (phone: 610/832-9717; email@example.com).