ASTM D3238 Calculation of Carbon Distribution and Structural Group Analysis of Petroleum Oils by the n-DM Method

Carbon distribution and ring content data are used in characterization of oils in the refining-manufacturing process and can also correlate to critical performance properties.  Refractive Index, Density and Molecular Weight (n-DM) are used to calculate the following values:

% CA Percentage of Aromatic Carbon  % CN Percentage of Naphthenic Carbon  % Cp Percentage of paraffinic Carbon  R_A Average Number of aromatic rings per Molecule  R_N Average Number of naphthene rings per Molecule R_T Average Number of rings per Molecule 

The mass % Sulfur must be determined in order to calculate values for R_T and R_N. The n-DM and Sulfur content are determined by the following:

Refractive Index (n)  ASTM D1218  Density at 20°C (d)  ASTM D1481 Average Molecular Weight (M) ASTM D2502 Sulfur Content (mass %) ASTM  D2622 

Applicability of the method is limited to the following: In terms of carbon distribution – up to 75% carbon atoms in ring form; % aromatic less than or equal to 1.5 times the % naphthenic rings. In terms of ring content – up to four rings per molecule with not more than half of them aromatic.

Price: $750.00

Sample size: 100 ml

Related tests:

• ASTM D1481 – Density by Lipkin Bicapillary Pycnometer up to 100°C – per temp
• ASTM D2502 – Molecular Weight from Viscosity – includes 100°F and 210°F viscosities.
• ASTM D2622 – Sulfur by X-Ray Fluorescence (WDXRF)