A master clock is a hardware device that obtains accurate time from a hardware reference and synchronizes slave clocks and time displays. The slave clocks rely on the master clock to display the correct time.
Once set, traditional, unsynchronized clocks drift away from the correct time at differing rates. After a relatively short amount of time, they can all display very different times. Correcting individual clocks can be a very time-consuming process which needs to be carried out at regular intervals.
GPS Master Clocks
Master clocks can use hardware time references, such as the GPS system to obtain very precise time. GPS is accurate to one-second in three hundred million years. Therefore, all time displays and slave clocks can refer to a highly accurate, legally traceable source of time. GPS systems require an antenna that is typically located with a clear view of the sky. Alternatively, where antenna installation is difficult, public internet Network Time Protocol (NTP) servers can be used.
Everyone Works To The Same Time
Many organizations can benefit from synchronized clocks. Staff all work to the same time, therefore meetings can start promptly, classes in schools start and finish as scheduled and shifts start and end consistently. Hospitals, manufacturing and pharmaceutical industries can accurately log events.
Once installed and correctly configured, slave clocks are virtually maintenance free in contrast to high-maintenance stand-alone clocks.
In many countries, clocks need to be adjusted twice a year to correct for daylight saving time. If a large number of clocks need correcting, it can be very time-consuming. Often clocks are located at height or in inaccessible positions that makes the task even more time-consuming. Additionally, adjustment often takes place well after the event, clocks will therefore be incorrect for an extended period.
Master clocks adjust for daylight saving time automatically, requiring no manual user intervention. Additionally, all clocks adjust at the correct moment so that a continuously accurate time is displayed.
An added advantage is that slave clocks can often be configured to display time in different time-zones, ideal for trading floors and meeting rooms.
Power outages or failures can cause unsynchronized clocks to become inaccurate. Each clock must then be corrected individually. Master clock systems automatically obtain accurate time from hardware references such as GPS. Within minutes of the power being restored, slave clocks will be back up and running. Often no operator intervention is required.