The most accurate is the atomic clock, because the definition of a second is the duration of 9,192,631,770 cycles of radiation corresponding to the jump between two hyperfine energy levels in the ground state of the cesium 133 atom... So he's the most accurate...
Electronic watches are not accurate... Mechanical watches are even worse, chronometer grade is good... A day's error is basically in -4 ~ +6 it, the general day error + - 15 seconds ~ 30 seconds ranging (the price of thousands of dollars of error is also about 30 seconds)
Electronic watch accuracy has improved a lot, but still can not ah, the electronic watch there is a problem with the price, that is, there are 10 yuan, more than 1,000 yuan, remove the advantages of the brand is also a lot of difference, this is the internal technology of the electronic watch! The problem. The quartz watch, the vibration crystal quality in addition to the special case, the daily error of +,- a second or less. The computer is more accurate, and the Internet can be updated at any time and automatically adjust the time