(NIST: Gaithersburg, MD) -- The National Institute of Standards and Technology (NIST) has issued a new ruler and even for an organization that routinely deals in superlatives, it sets some records. Designed to be the most accurate commercially available “meter stick” for the nano world, the new measuring tool—a calibration standard for X-ray diffraction—boasts uncertainties below a femtometer. That’s 0.000 000 000 000 001 meter, or roughly the size of a neutron.

The new ruler is in the form of a thin, multilayer silicon chip 25 millimeters square (just under an inch). Each one is individually measured and certified by NIST for the spacing and angles of the crystal planes of silicon atoms in the base crystal.

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