The picture is of the US National Prototype Kilogram. It is made of 90% platinum, 10% iridium. It was assigned to the US in 1889 and is periodically recertified and traceable to "The Kilogram" held at BIPM near Paris.
Manufacturing Metrology Division Free use of this photo is restricted to materials that
describe NIST programs directly. Copyright is owned by the photographer. To
receive an unwatermarked copy of the photo for use describing NIST programs
contact Beamie Young. To use the photo as stock photography
contact: Robert Rathe Photography, 9125 Kristin Lane, Fairfax, Va., 22032,
(703) 425-3442.
20912
|
