Control Engineering

Peter Welander

More on the kilogram and off to St. Louis
October 22, 2007

This morning I received a reply from MSgt. Dan Marshall, USAF:

"Hey Pete,

I read your article about the standard for a kilogram and have a question. Is the unit of measure of one gram not one cubic centimeter (1 ml) of pure water at 4 degrees Celsius? 

The link I found refers to the one in Paris as a 'model'.  As far as using carbon atoms as a reference, I kind of like the use of water.

Have a great Air Force Day. I am."

Sgt. Marshall is referring to the story that ran in last week's Process Instrumentation & Sensors Monthly about the standard Kilogram losing weight. It explores the nature of standards in general, for the sake of those of us who have had to deal with instrumentation calibration. (I never made it past corporal in my brief and unremarkable career in ROTC.)

Have a great Air Force Day, sir, as well. I will ponder this further as I sit in the car this afternoon and evening, motoring to St. Louis to attend the GE Fanuc User Conference. I will return to these musings on Thursday.

Posted by Peter Welander on October 22, 2007 | Comments (0)