Advances in quantitative analytical ferrography and the evaluation of a high gradient magnetic separator for the study of diesel engine wear

Several sources of variation in quantitative analytical ferrography are investigated. A standard ferrography analysis procedure is developed. Normalization of ferrographic data to account for the amount of oil used to make the Ferrograms is discussed. Procedures to minimize the errors involved in calculating three quantitative ferrography parameters, i.e. the area AL (% (ml of oil)-1) covered by the large particles, the area AS (% (ml of oil)-1) covered by the small particles and the area under the curve (millimeters per cent per milliliter of oil) are outlined. Ferrographic data are presented which show that the volume and dilution ratio of the oil sample being analyzed have a major effect on the accuracy of the analysis. Several variables which influence the area-covered readings of the particle deposit on a Ferrogram are discussed. The accuracy of quantitative analytical ferrography is assessed. Quantitative analytical ferrography is used to evaluate a high gradient magnetic separator (HGMS), both as a tool for engine wear research and as an oil filter. Laboratory tests indicate that the HGMS is an order of magnitude more efficient than conventional paper oil filters in removing magnetic wear debris from the lubricating oil