COMPARISON: FINE TEST DUST
Seven samples of ISO Fine Test Dust manufactured by Powder Technology Inc. and six samples of AC Fine Test Dust manufactured by AC Spark Plug division of General Motors were analyzed for comparison.
The ISO Fine samples (formerly SAE Fine) selected are those previously used to determine particle size limits shown in ISO 12103-1 Test Dust Standard. ISO Fine batch ID numbers are 4377B, 4382A, 4400B, 4402B, 4422B, 4443A, and 4492B. Graph A indicates the cumulative volume spread of ISO Fine samples analyzed.
ISO 12103-1, A2 FINE TEST DUST GRADES
(Microtrac X-100 Cumulative Volume)
AC Spark Plug Fine Test Dust samples analyzed were selected randomly and included batch ID numbers 054, 258, 520, 958, 1125, and 1472. Graph B indicates the cumulative volume spread of AC Spark Plug Fine samples analyzed.
AC FINE TEST DUST
(Microtrac X-100 Cumulative Volume)
ISO Fine sample data was averaged, as was AC Spark Plug Fine sample data. Graph C compares the cumulative volume average of the two types of Fine Test Dust. Graph D compares differential volume averages of ISO Fine and AC Spark Plug Fine samples analyzed.
COMPARISON OF AVERAGES, FINE TEST DUST
(Microtrac X-100 Cumulative Volume)
COMPARISON OF FINE TEST DUST DIFFERENTIAL DATA
Review of Graphs A and B indicate a narrower spread among ISO Fine Test Dust samples as compared to AC Spark Plug Fine Test Dust samples. From this, we may assume that test results accumulated using ISO Fine Test Dust should be more consistent over time than those accumulated using AC Spark Plug Fine Test Dust. Graphs C and D indicate significant differences in particle size between the two types of dust. There is an increase in particle content below 1.5 microns and above 9 micron size when comparing AC Spark Plug Fine Test Dust to ISO Fine Test Dust. Inversely, ISO Fine has an increase in particle content between 1.5 and 9 micron size. The median particle size of AC Spark Plug Fine Test Dust is 10.65 micron, whereas, ISO Fine median particle size is 7.01 micron. Significant differences such as these could translate to performance differences when testing some products.
