[time-nuts] Ultra low phase noise floor measurement system forRF devices.

Didier Juges didier at cox.net
Sun Apr 1 01:38:13 EDT 2007


In France, and I suspect in the rest of the world, machinists talk in 
1/100th of a mm (centieme in French). The 'centieme' is a very good 
fractional unit when dealing with hardware. It is not harder to talk in 
1/100th of a mm than in 1/1000th of an inch. The micrometre (micron in 
French, as you correctly stated) is seldom used outside of metrology 
labs, optics and specialized applications.

After 33 years in France, and 22 here in the US, I must say I have not 
completely converted, by a long shot. The Imperial system is just too 
ridiculous. It is an offense to common sense. BTU/hr? please spare me :-)

The Brit's in their belated wisdom (they invented the Imperial system 
after all) decided to keep the old units for beer (pint) and do away 
with the rest. That's fine with me!

Interesting related event: the local grocery store has a ham cutting 
machine that has a dial calibrated in mm. This is apparently not 
uncommon in this country, these machines are probably imported. The 
other day, as I was buying ham, a new employee asked me how thick, so, 
of course, I said 1.5 mm. You should have seen the look on his face, he 
had no idea what I was talking about. So I told him it was lingo for 
putting the dial between 1 and 2, so he just turned the dial and did not 
ask any question...

Didier KO4BB


John Miles wrote:
> The other reason the machinists aren't thrilled with SI units is that
> thousandths of an inch are actually a pretty good match for the precision
> they usually deal with.  In SI, you'd have to deal with micrometers
> (microns?), which is too much resolution for most applications, or
> millimeters, which is nowhere near enough.
>
> -- john, KE5FX
>   




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