ABSTRACT
This chapter describes the National Bureau of Standards’ Certification of SRM 1960: Nominal 10 μm Diameter Polystyrene Spheres ("Space Beads"), relating the context in which the publication appeared, its impact on science, technology, and the general public, and brief details about the lives and work of the author. To certify SRM 1960, the so-called "space beads", researchers at NBS, led by Tom Lettieri of the PED, developed three new particle-sizing techniques, which are described in the publication Certification of SRM 1960: Nominal 10 μm Diameter Polystyrene Spheres ("Space Beads"). These techniques were center distance finding (CDF), resonance light scattering (RLS) from a liquid suspension of microspheres, and metrology electron microscopy (MEM). The microspheres were spread onto a slide such that they formed long chains of contacting spheres, rather than the regular hexagonal arrays formed in conventional array sizing.
