Test Sieve & Screen Tray Verification & Services - Gilson SS-12R Operating Manual

Gilson Company, Inc.
best choice where contamination, sanitation or extreme
wear is an issue.
• Brass Frame with Stainless Steel Cloth is a popular choice
that offers extended service and cost-effectiveness.
• Brass Frame with Brass Cloth is economical for light-
duty applications. Coarse-series sieves are not available
with brass cloth.
Backing Cloth
Back-up cloth prevents sagging or tearing of expensive
fine stainless steel mesh. Unsatisfactory service life from
a sieve would suggest replacement by a sieve built with
backing cloth. To order, add the code "BU" to the model
number of the sieve. These sieves are made-to-order,
have longer delivery times and are non-returnable.
Pans and Covers
• Pans collect fines at the bottom of the sieve stack.
Extended-Rim pans are also available to insert into the
middle of a stack, allowing two samples to be tested at
once.
• Covers are not necessary with most Gilson sieve shakers,
but may be needed if using a different shaker or shaking
by hand. The Cover-with-Ring has a wire finger loop in the
center to facilitate removal.
Gilson Sieve Verification Services
Gilson Verification can be performed on any test sieve
or Gilson screen tray, used or new. These services are
ordered by specifying the appropriate model number given
in our listing for Test Sieve and Screen Tray Verification
and Services. An optical comparator with NIST traceable
calibration measures opening sizes and wire diameters
on each sieve, and a statistical analysis assures the
standard deviations are within ASTM or ISO requirements
for Inspection or Calibration grades. Sieves, trays, or
wire cloth units are not included in the purchase price of
the verification services. Because wire cloth stretches,
sags, or tears, and abrasive materials can reduce wire
diameters, a verification process should also be set
up to regularly verify that working sieves still meet the
specifications. These measurements can be taken directly
using calipers or an optical comparator, by testing with
Standard Reference Materials, or by returning to Gilson
for Re-Verification. To verify used sieves, contact a Gilson
customer service representative for shipping instructions.
Standard Reference Materials (SRM's)
Sieve Reference Materials are precision glass beads
or powders for performance testing of sieves. They
are traceable to the National Institute of Standards and
Technology (NIST), or European Community Bureau of
Reference (BCR). SRM's fit easily into internal quality
programs following guidelines in ASTM E 2427, Sieve
Acceptance by Performance Testing. User-Prepared
Reference Materials can also be utilized under E 2427
in the same manner as SRM's. Because user materials
are non-standard, they are not traceable and require
much more handling. In addition, the user must determine
acceptable tolerances for statistical analysis.
Sieve Shakers
The proper sieve shaker saves considerable time and
effort, and yields superior accuracy, consistency, and
repeatability compared to manual shaking methods for
particle sizing. Effective agitation lifts all particles off
the sieve cloth, reorients them, and allows them to be
repeatedly "tried" to different openings at different angles.
Careful review of shaker specifications allows optimal
choices for different materials and applications. Greater
sample volumes and large particle topsize may indicate
selection of Gilson Test-Master
Screen models for efficient processing.
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8.2 Test Sieve & Screen Tray Verification & Services
There have been extensive revisions to the newest
version of ASTM standard E 11, Specification for Wire
Cloth and Sieves for Testing Purposes. Gilson is leading
the way in educating our customers about the new
specification and making these new products available.
The new specification affects all test sieves, screen trays,
and wire cloth, and changes the way the mesh openings
are evaluated by looking at the statistical distribution
of aperture sizes, rather than just the average opening
sizes. In addition to a more accurate and reliable system
of evaluation, the new system also allows compatibility
with ISO 565 and 3310-1 requirements. There are now
three grades, or classes of ASTM or ISO test sieves
available; Compliance, Inspection and Calibration.
• Compliance Test Sieves are manufactured with wire
cloth that has been inspected and measured in roll
or sheet quantities prior to being cut and mounted
in the individual sieve frames. Opening sizes are
not measured in individual sieves. Each Compliance
sieve is supplied with a certificate of manufacturing
compliance, but no statistical documentation is given.
Compliance sieves are designed for applications where
a basic, reliable degree of accuracy and repeatability
are sufficient.
• Inspection Test Sieves have a specified number of
openings measured in each sieve after the cloth is
mounted in the frame. There is a 99% confidence level
that the standard deviation of these openings is within
the maximum allowed by ASTM. Inspection Sieves
are a good choice in applications where accuracy and
repeatability are critical. Each Inspection Sieve consists
of a Compliance Sieve with added Inspection Sieve
Verification service.
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Gilson Sieve Shaker: SS-8R & SS-12R
, Testing Screen or Porta-
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