Because accuracy and precision are vital components of any Quality Control Program, VWR® Pre-Certified Sieves ensure compliance with the American Standards Testing Materials (ASTM) E11 specifications.
- 1" Half height or 2" Full Height
- ASTM E11 Inspection Grade Certification (99.0% Confidence Level)
VWR® Pre-Certified Sieves employ sophisticated software and optical technology that scans for irregularities and takes physical measurements in a midpoint orientation of the wire in the “X” and “Y” directions (warp and weft)
The current ASTM E11 standard offers two available grades of pre-certified sieves (inspection or calibration). Inspection Grade sieves are supplied with a Sieve Inspection Certificate containing inspection data that has a percentage of openings and wire dimension measured based on the ASTM E11 standards table providing a confidence level of 99.0% that each sieve is within the specifications. Calibration Grade sieves are supplied with a Sieve Calibration Certificate containing data of at least twice as many apertures measured than inspection sieves, thereby providing the highest confidence level available of 99.73%.
As with other precision lab instruments, periodic re-certification is recommended to ensure the continued conformance and accuracy of working test sieve. Working sieves that are used regularly will eventually suffer wear that may produce inaccurate test results. The intervals for sieve re-certification depend greatly upon frequency of use, sample material properties, handling and cleaning processes, and internal quality system requirements. For a “Recommended Test Sieve Re-Certification Schedule”, please view the RELATED INFORMATION tab. Sieve Pre-certification is performed on new sieves. Sieve Re-certification is performed on existing or working sieves and must be sent to VWR's facility for evaluation. Please contact your VWR® Sales Representative for details.
The data gathered is summarized in a comprehensive verification report that is linked to each serialized sieve and evaluates exactly where the sieve lies in relation to the ASTM E11 standards. Verification reports identify a trace number that measurements taken are traceable to the National Institute of Standards and Technology (NIST).