Measurement is one of the holy grails of science. Without it, science would be impossible. But ensuring measurements are accurate and consistent can be a major challenge. This is especially true for national and international standards. While much has been done in recent years to ensure global accuracy, this effort is in its infancy. One of the most well known standards is the kilogram. Last updated in 1889, the kilogram has finally been altered for the first time on May 20, 2019.
The French National Institute of Metrology (INM) has proposed that the kilogram be redefined using a new methodology. The goal is to ensure the kilogram remains accurate and accepted on an international scale. But why the dramatic change? To the average person, the kilogram is simply a unit of measure. To engineers, scientists, and physicists, the accuracy of the kilogram is fundamental to verifying measurements.
Due to the world’s changing environment, the accuracy of the kilogram has to be recalibrated constantly. In order for measurements to stay accurate, the kilogram must be precisely defined. This is why the organization behind the kilogram decided to use advances in measurement technology to redefine the standard.
The new kilogram is defined using a piece of machinery called a Kibble balance. The Kibble balance is a microscale instrument that measures mass using the force of electric current. Even the slightest changes to the force of the current are detected, which gives the Kibble balance staggering accuracy. In fact, the Kibble balance is 1,000,000 times more accurate than the old kilogram was prior to being redefined.
As of today, the definition of the kilogram is based on a physical prototype. This prototype was created in 1889, and has been kept in a vault at the International Bureau of Weights and Measures. Since that time, this physical replica has been the definitive reference for the kilogram. However, due to the problems of not being able to access it, the prototype is slowly losing mass. This loss has caused a discrepancy between the scales, furthering the need for a new definition.
Advantages Of The Kibble Balance
The Kibble balance has multiple advantages compared to the old prototype. Not only is it much more accurate, it is also widely accessible. To use the Kibble balance, all one needs is a local electricity supply. Additionally, the exact same measurement can be duplicated anywhere in the world without the variance a physical prototype would have.
The output of the Kibble balance is direct current of a certain voltage, meaning power can be used to directly read how much mass has been measured. This eliminates the need for guesswork, and allows measurements to be incredibly accurate.
A Key Moment Of Change
It was a historic day when the new kilogram was adopted. Representatives from around the world gathered at the General Conference on Weights and Measures to pass a resolution that would redefine the kilogram. The new kilogram was defined as: “The kilogram, symbolized kg, is the SI unit of mass; it is equal to the mass of the international prototype of the kilogram”. It was a revolutionary decision that would ensure the accuracy of the kilogram for generations.
An Institute Of Measurement
The International Bureau of Weights and Measures (IBWM) is the main decision-making body behind defining units of measure. Created in 1875, the IBWM is responsible for setting and maintaining the global standard for measurements. It does this by regularly checking on physical prototypes, as well as using the best technology available. This is why they opted to redefine the kilogram before it became useless.
Modernization Of The Kilogram
The Kibble balance is a significant step forward for the accuracy of the kilogram. It has enabled us to redefine the kilogram in such a way that it won’t need to be recalibrated for many years. The Kibble balance also has a major benefit in that its readings are much more consistent and doesn’t arise with the discrepancies of a physical prototype. Weighing with a Kibble balance is now the accepted standard for measuring mass.
A Global Standard Of Measurement
The kilogram is just one of many physical objects used to define units of measure. The other standards include the ampere, the kelvin, the metre, and the candela. The only thing that’s constant in the world of measurements is that they change. To keep up with these changes, the IBWM regularly consults with numerous scientific and mathematical experts to make sure the standards stay accurate.
The End Of The Prototype Kilogram
With the new kilogram in effect, the old prototype kilogram is no longer needed. This is both a good and a bad thing. On one hand, it won’t need to be reinstalled in order to stay accurate. On the other hand, its historical significance and heritage are gone forever. It was a unique physical object that served as a valuable reference for more than a century – one that we can’t get back.
The Future Of The Kilogram
Since the kilogram is just one of seven base SI units, its accuracy is paramount for keeping the system consistent. Now that the kilogram has been redefined with the Kibble balance, scientists around the world can rest assured that the kilogram will remain an accurate standard for many years to come. Measurement is the foundation upon which science and progress is built, and it is the job of the IBWM to make sure these standards are secure and accurate.
