What is the official definition of 'aperture'?

The opening between the wires (for wire cloth sieves) or the opening in the plate (for perforated plate sieves), as defined in Clause 2.3.1.

What is the difference between 'blinding' and 'clogging' of a sieve?

Blinding (Clause 2.5.3) is when particles close to the aperture size get wedged in the openings, while Clogging (Clause 2.5.4) is when particles adhere to the surface of the sieve medium itself.

What defines a 'Test Sieve'?

A sieve intended for particle size analysis which conforms to specific national or international standards regarding its construction and accuracy (Clause 2.2.1).

What is 'End Point' in a sieving test?

The point at which the rate of passage of material through a sieve becomes negligible, indicating the effective completion of the sieving operation (Clause 2.4.6).

IS 5421

: 2013

Glossary of terms relating to testing sieves and test sieving

CurrentFrequently UsedTerminologyMaterials Science · Sieves, Sieving and Other Sizing Methods

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This standard provides a comprehensive glossary of terms related to test sieves and the process of test sieving. It aims to standardize the vocabulary used in particle size analysis to ensure uniform understanding and interpretation of procedures and results.

Glossary of terms relating to testing sieves and test sieving

Practical Notes

Crucial to differentiate between 'nominal aperture size' (the target dimension) and 'average aperture size' (the statistical average of actual openings), as manufacturing tolerances always exist.

Understanding terms like 'blinding' (particles getting stuck in apertures) and 'clogging' (particles sticking to mesh wires) is key to troubleshooting inaccurate sieving results.

This glossary is the foundation for correctly interpreting specifications in test method standards like IS 460 (Test Sieves) and various material testing codes.