FILTERS BALDWIN

Catalog Baldwinfilters for tractors

Auto Parts / FILTER PERFORMANCE

MICRON RATINGS A life and efficiency test measures the
filter’s ability to remove a standardized
contaminant from a standardized fluid
Micron Ratings are arbitrary values
assigned to filters or media. Although a that is flowing at a constant rate and
“micron” is a length (1 millionth of a constant temperature. The test
meter), a “micron rating” is not actually continues until the contamination
a measured value. The micron rating increases the differential pressure
for a filter quotes a particle size without drop across the filter to a specific,
establishing the filter’s efficiency at predetermined level. The test results
removing that size of particle. A window will include a Time Weighted Efficiency
screen will remove some 5 micron (%) and a Capacity (grams).
particles, but it will not be very efficient. BETA RATIO TESTS
Since a micron rating cannot be
verified, filter manufacturers are safe in
assigning any number they want. We Beta Ratio Tests measure a filter’s
do not recommend comparing filters ability to remove particles of a given
based on micron ratings. size. In other words, the tests measure
the filter’s efficiencies at specific particle
To compare filters, the filter industry has sizes. The beta ratio test actually
established standardized tests for counts the particles in the fluid before
measuring performance. These tests also the filter and after the filter. This test is
include Life and Efficiency Tests (SAE generally done on hydraulic filters.
HS806, J726 and J905) and Beta Ratio
Tests (ISO 4548-12 and ISO 16889). SUMMARY
These standardized tests, along with the
meticulous recording of test conditions, In summary, equipment owners should
insure that filter manufacturers compare consider all of the factors when
“apples to apples.”
choosing filters for their applications.
You should try to closely follow cross-
LIFE AND EFFICIENCY TESTS reference and specific application
recommendations. When comparing
Life and Efficiency Tests are the filters, you should note the questionable
most accurate and objective way to nature of micron ratings and try to get
compare the performance of filters. standardized test information.
BETA RATIO
ß = particles upstream = 20,000 particles = 20
particles downstream 1,000 particles
Using the following formula and following the examples, you can convert a beta
ratio to an efficiency:
ß-1 x 100 = Efficiency (%) = 20-1 x 100 = 95%
ß 20
Examples: ß10 = 2: (2-1) ÷ 2 x 100 = 50.0% efficient at 10 µm
ß15 = 75: (75-1) ÷ 75 x 100 = 98.7% efficient at 15 µm

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