Skip to comments.A weighty problem: The official kilo is getting heavier
Posted on 01/09/2013 7:21:44 AM PST by null and void
In a vault in suburban Paris sits the official kilo, the 124-year-old standard from which numerous other measurements are derived.
Even in the carefully controlled and protected environment, contamination has built up on the surface of the object. The increase in mass is tiny but the effect on science is real.
Unfortunately, the laymans solution of simply washing the cylindrical item isnt so easily done. So a pair of United Kingdom scientists has come up with an elaborate 30-hour procedure, a combination of rinsing, ultraviolet light and heating that promises to return the kilo to its true mass.
Around the world, the IPK and its 40 replicas are all growing at different rates, diverging from the original.
The IPK was created in 1879. The cylinder has a diameter of 39.17 millimetres and is as tall as it is wide. It is an alloy of 90 per cent platinum and 10 per cent iridium.
The relevance of the IPK cascades through science. For example, a newton is defined as the force required to accelerate a kilogram at a rate of one metre per second squared. If the IPK changes, so must the newton. And the newton is the basis for the pascal, the ampere and the joule, which is used in turn to determine the watt.
Any work also must be done very delicately, removing the surface contamination but not even the thinnest layer of the material itself.
This would clearly be disastrous in the treatment of platinum-iridium or other noble metal mass standards, where a single layer of atoms on the surface typically represents a mass of 30 [micrograms], and must not be sacrificed, the authors write, noting that 30 micrograms is at least ten times the accuracy with which mass standards can be compared.
(Excerpt) Read more at theglobeandmail.com ...
Yeah, you're not getting fatter, you're collecting dust...
Being from a metrology background, I can understand the importance of this problem.
A few years back, the NIST (formerly the NBS) was working on an electrical representation for mass / force using a huge magnetic coil type device. I guess they still have not perfected this standard.
It basically would be a device that would exert a certain amount of force when a known current was passed through the coil...........
The high point of my career was making a silicon IR photodiode that forced the NBS to recalibrate its standards.
It was either that or admit my sensor had better than 100% quantum efficiency...
They had better make it 29 hours to keep it out of the Obama non affordable health care clutches.
but what will this mean for drug dealers?
Leave it to science to make a mountain out of a mole hill.
...and they told us in school that ‘NBS’ stood for No Bull $H!T!.............
There was an article last year on the NIST effort with magnetic coils, and a competing team from Germany trying to come up with a new standard:
The culprit is clearly gravitational increase brought on by mankind’s addiction to fossil fuels and flash suppressors, not to mention archaic, patrimonial definitions of marriage and the right of all women to be killed in the womb. Only Al Gore can save us now, or maybe Lance on Oprah.
Wouldn’t the force change it the coil gathers contaminaton?
No, it’s sealed........