The Blotter Test is used to determine the insoluble contaminants, dispersant ability, and alkalinity of used oil from
diesel engine samples. This test is performed by placing one drop of used oil in the center of an oil print filter circle. The
oil spot is allowed to develop for 15 minutes, and the resulting spot is evaluated for total contaminants, cooling
contaminants, and dispersant effectiveness. An alkalinity indicator is added to the spot and, after one or two minutes, the
alkaline reserve is determined from the color ring that develops.
The Flash Point Tester is used in determining the percentage of fuel dilution in used oil samples from diesel
The Microscopic Analysis Test is used to determine wear and contamination of suspect spectrometric oil samples
from aircraft components as relates to the components condition. This is accomplished by placing a few milliliters of the
suspect oil sample in a test tube and mixing with solvent. This mixture is then filtered through a .01 45u (Micron)
membrane filter. The remaining insoluble debris and filter membrane are carefully rinsed with solvent to remove oil and
then allowed to air dry. The dry membrane is transferred to a petri slide and the debris examined under a low-power
microscope. The debris are identified as to type of wear metal with respect to wear and contamination.
Ferrographic analysis is currently performed on selected aeronautical components (i.e., AH-l swashplates and
Scissors & Sleeves Assembly) as a supplement to spectrometric analysis.