CEH 008

Swiss Watch Fair 1967 BF/CEH 8
Detailed view of the receptor-clock the Horological Electronic Center (CEH) presented in Basle. This clock receives the time-signal emitted by the Prangins transmitter (theoretical range 900 to 1200 miles) and automatically corrects its own possible rate. The Prangins time-signal is itself controled by an atomic clock with a precision of the order of one millionth of a second per day.