Arbiter Systems Portable Power Sentinel 933A, Руководство по эксплуатации

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3.3 Clock Time Set
3.3.1 Internal Real-Time Clock
Before making measurements, take time to set up the real-time Clock. Ca-
pable of operating in three different modes, each clock mode offers different
performance advantages. Whatever mode you ultimately decide to use, it
is important to understand the performance differences, and to configure
the clock so that the clock performance matches your expectations.
Figure 3.4: Clock Setup
Clock Operating Modes
There are three clock-operating modes from which to choose: (1) free
running, (2) synchronized to the GPS, and (3) synchronized to IRIG-B.
For a complete list of specifications, please see Chapter 8.
Free Running
Clock time is based on the internal oscillator, with no external timing input
for stabilization. Clock time depends on initial setup, with a characteristic
drift of less than 1 second per day.
Synchronized to an External IRIG-B signal
Uses an IRIG-B signal from an external clock to synchronize the internal
clock of the 933A. Accuracy: Better than 1 microsecond plus the accuracy
of the IRIG-B source.
Synchronized to an External GPS Signal
Use the accessory GPS module (see Section 1.4.13) to synchronize the
internal clock of the 933A to the GPS time standard. Accuracy: Better
than 1 microsecond.
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