킬로그램(kg) 정의 130년 만에 바뀐다
Today is World Metrology Day,... when the world celebrates the weights and measures established under the International System of Units.
And to mark the occasion, the kilogram has been redefined after 130 years.
Our Choi Si-young has the details. Scientists have come up with a new, more accurate standard for defining the kilogram.
The current kilogram standard is the mass of a cylinder known as Le Grand K, which has a height and diameter of just over 39 millimeters and is made of 90 percent platinum and 10 percent iridium. It is stored in a vault outside of Paris.
However, the processes of oxidation and hydrocarbon contamination have added mass to the cylinder over the last 130 years.
The fine change in mass is crucial to the pharmaceutical and biotechnology industries, which need accurate measurement.
Starting May 20th, the World Metrology Day, the kilogram will be redefined by a new standard maintained by the Kibble balance.
The balance measures the electric current required to support the weight of a standard kilogram mass in a magnetic field.
Because the balance has a fixed value, it can precisely measure the weight of an object.
Korean researchers are also working on reducing the measurement uncertainty of the locally-developed Kibble balance.
"The accuracy of South Korea's Kibble balance is slightly behind that of the world standard of the U.S. and Canada. But, with further studies done over the next four to five years, we expect to reach that world-class accuracy."
The change to the standard of mass will be crucial for high-tech industries such as semiconductor sectors,… but researchers say that the change will not have a noticeable effect on our daily life.
Choi Si-young, Arirang News.
