Whitehouse Sieve Standards provide a unique method of calibrating 8in diameter No.6 (3.35mm) and finer sieves with traceability to NIST. The high speed calibration method can be done in the lab in about two minutes per sieve. Sieves need not be taken out of service until indicated by the user's test results. Periodic checks with Standard Reference Materials serve as an indicator of when to replace or return sieves. Each Sieve Standard comes as two to five pre-sampled single-use vials of glass beads for use with a single sieve size. After shaking a vial of beads, test sieve, and pan in a prescribed manner, the average aperture is quickly read from the calibration graph provided. Because of the very narrow size distribution of the samples, each five percent weight difference is usually equivalent to about one micrometer in mean sieve aperture, allowing a precise calibration.

Whitehouse has been producing high-precision glass microspheres for research and calibration for nearly 20 years and has been selected by the Community Bureau of Reference (BCR) to produce standards for the European Community. Today's Whitehouse Sieve Standards are traceable to NIST and NPL as well as to BCR. The highly spherical beads are made from 2.45 specific gravity sodalime glass and certified for size using electroformed sieves with checks using microscopy and image analysis