Sieve Services assure conformance of your Test Sieves and Screen Trays to their respective specifications. All Gilson ASTM and ISO Test Sieves start as Compliance Grade sieves complete with serial numbers and certificates of conformance with manufacturing practices, but no specific statistical data is given. Compliance sieves are the standard model and have a statistical confidence level of 66% that the standard deviation of openings meets E11 requirements.
For applications requiring greater accuracy or traceable documentation, Compliance Sieves can be verified as Inspection or Calibration Grade sieves. These sieves feature progressively higher levels of probability (99% and 99.73%, respectively) that the standard deviation of openings in an individual sieve meets E11 requirements. When an Inspection or Calibration Grade sieve is ordered, a Compliance Grade sieve is selected from inventory and verified to either of the selected grades.
Gilson offers a variety of additional Sieve Services for advanced precision needs.
- Verification of New Sieves to Inspection or Calibration grade carries an additional charge and is specified when sieves are ordered. Each sieve is individually measured on an NIST traceable optical comparator prior to shipment. A computerized system automatically scans the sieve, performs a statistical analysis and provides required documentation appropriate to the grade desired. Periodically returning sieves or screen trays to Gilson for Reverification assures continued compliance with standards.
- Reverification of Used Sieves follows the same process as the Verification of New Sieves, but the evaluation is performed on existing sieves. This process confirms that your operational sieves remain in compliance with ASTM or ISO standards. The required measurements are performed and a statistical analysis is supplied along with each sieve’s Inspection or Calibration Verification Certificate.
- Master-Matched Sieves are ideal when correlating sieving results from multiple testing labs. Each Master-Matched sieve is matched through measurement and performance testing to a master sieve from our reference laboratory, assuring openings will be within a narrow range. Using matched sieves in different locations assures consistent results. Master-Matched Sieves are available only in 8in stainless steel frames in ASTM E11 sizes from No. 8 through No. 325 (2.36mm through 45µm). Inspection grade verification to E11 is included with each sieve.
To learn more about how to verify test sieves, read the Gilson Insights blog post, A Guide to Acing the Sieve Grade Selection Process