Atomic clocks show up on surplus auctions/stores somewhat frequently (they’re called a Caesium frequency standard, e.g. the HP 5071). There’s a few reports of enthusiasts keeping them running at home (http://leapsecond.com/ptti2003/tvb-Amateur-Timekeeping-2003....)
I’m sure HP/Agilent/others will gladly sell you the newer state of the art modes as well (although as high precision, very low volume devices they’ll be fabulously expensive); if an industry consortium wants even more precision you could staff a research team and shave off a bit more frequency error.
However, I think for industry it’s cheaper to use GPS receivers instead of supporting a powerful transmitter (and its use of value able spectrum). GPS can keep incredibly accurate time.
I’m sure HP/Agilent/others will gladly sell you the newer state of the art modes as well (although as high precision, very low volume devices they’ll be fabulously expensive); if an industry consortium wants even more precision you could staff a research team and shave off a bit more frequency error.
However, I think for industry it’s cheaper to use GPS receivers instead of supporting a powerful transmitter (and its use of value able spectrum). GPS can keep incredibly accurate time.