Patent ID: 7807467

Claim:
A method for predicting the High Frequency Reciprocating Rig (HFRR) wear scar diameter for a diesel product comprising the steps of: (a) selecting a control diesel product having various measured HFRR wear scar diameters as measured using the test method ASTM D-6079; (b) subjecting each of said control diesel products to mid-infrared (MIR) spectroscopy testing to thereby produce control property results for each of said control diesel products; (c) selecting an interaction model equation comprising a plurality of terms which relates MIR spectroscopy property results to HFRR wear scar diameters wherein said interaction model equation is based on multi-linear regression (MLR) analysis having the form P x =M 0 +M 1 F 1 +M 2 F 2 + . . . M z F z ; where P x =value for property x; which corresponds to an HFRR wear scar diameter F z =absorbance value from filter z; which correspond to said terms M z =parameter estimate from filter z based on MLR analysis; which correspond to said coefficients for said terms M 0 =intercept of model; and wherein the interaction model equation has 14 filters corresponding to the following functional groups: F1=methyl F2=methylene F3=Alkyl nitrate/Naphthalenes F4=Filter 3 baseline correction F5=Aromatic F6=Alkene F7=Alkene F8=Naphthalenes F9=Aromatic 3 adjacent hydrogens/Naphthalenes F10=Aromatic 4 adjacent hydrogens F11=Biphenyl F12=Aromatic symmetrical tri-substituted F13=Aromatic 5 adjacent hydrogens F14=Polynuclear Aromatics (d) establishing an HFRR wear scar diameter prediction equation by: (1) determining a set of coefficients for said terms of said interaction model equation by applying regression techniques to said control property results and said measured HFRR wear scar diameters, and (2) testing the statistical significance of each of said coefficients and said corresponding terms, and retaining from said interaction model equation only those of said coefficients and corresponding terms which are statistically significant, to thereby establish said HFRR wear scar diameter prediction equation; (e) subjecting said diesel product to MIR spectroscopy testing to thereby produce MIR spectroscopy property results; and (f) predicting the HFRR wear scar diameter value for said diesel product using said MIR spectroscopy property results in said HFRR wear scar diameter prediction equation.