The international prototype and its copies are 90% platinum and this element is known to catalyse chemical reactions; perhaps there is some model that could explain the observed phenomena (but see below). In addition, a study has shown that mercury in the atmosphere will bond to a platinum surface. Ultimately, the BIPM is putting its primary effort into supporting the linking experiments that will allow a redefinition of the kilogram in terms of a fundamental constant of physics.
ここで疑問が (スコア:1)
原器自体が高価な貴金属ですよね。
保存は厳重管理されるはずだし、酸化防止のため、真空もしくはアルゴンで満たされた容器などに保存されるはず。
汚れとは一体なんだろうか?
無造作に、デスクに放り出していたのだろうか?
Re:ここで疑問が (スコア:2)
BIPM FAQ why are the international prototype and its copies diverging in mass? There must be some explanation [bipm.org]
ごく微量に大気中に存在する水銀の影響が考えられるようです。どれだけ清浄な状態で保管していても、表面吸着による汚染をゼロにはできませんから。