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COMPARISON OF AC SPARK PLUG
AND ISO 12103-1 TEST DUSTS
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Many test dust users have expressed an interest
in correlation between AC Spark Plug Fine and Coarse
test dusts formerly manufactured by AC Spark Plug and
ISO Fine and Coarse test dusts manufactured by PTI. Recent
particle size analysis of AC Coarse, AC Fine, ISO Coarse,
and ISO Fine Test Dust samples indicate differences,
which could translate to variations in testing performance.
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The above two studies involve
particle size data generated using a Leeds & Northrup
Microtrac Model X-100 laser diffraction type analyzer.
The Microtrac X-100 analyzer is capable of measuring
particulates between 0.12 and 704 micron size. The principle
of operation involves projection of a laser beam through
a transparent sample cell containing a stream of moving
particles suspended in water. Light rays, which strike
particles, are scattered through angles inversely proportional
to particle size. A photo detector array measures quantity
of light (flux) at predetermined angles. Electrical signals
proportional to measured light flux values are processed
by a computer system to form a multi-channel histogram
of particle size distribution. A secondary high angle
lens system and photo detector gathers high angle scattered
signal data from small particles. This data is merged
with large particle signal data and correlated into a
composite distribution. The Microtrac Analyzer was selected
for this particle size comparison because it provides
a rapid, repeatable means of comparing broadband distributions.
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FINE TEST DUST COMPARISON
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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.
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Graphical Comparison of ISO 12103-1 Test Dust Grades
Based on ISO 12103-1 Specified Limits Median
(Cumulative Volume)
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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.
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Click to Continue...
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