If the automatic clock synchronization option (LoggerNet [version 4] Setup, Datalogger, Clock tab) is used, do not set the Allowed Clock Deviation too tight (for example, 1 s), as the PC will try to change the clock either because of drift in its own clock or because of delays in the communication from the PC to the data logger. If the clock is updated too often, there is the risk of the data logger skipping records if the time is pushed forward just before it is supposed to store data.
Although most PCs are usually synchronized with Internet time, the default update time is several days, and a PC can typically drift tens of seconds in that period.
Clock issues also appear when changing to or from daylight saving time, as the data logger does not automatically adjust for DST. Data continuity can be maintained by keeping data logger clocks on standard time.
In addition, if the data logger’s internal 3 V battery is bad and the data logger’s main 12 V power supply is cycled, the data logger’s clock will reset to a default time.