Arbiter Systems 928A User Manual page 49

Note that the 928A is very flexible and always com-
pares the signals at channels A and B for their phase
relationship, regardless of the type of signal, whether
voltage or current.
Phase Conventions
The following chart illustrates the standard phase con-
ventions as used in the Model 928A. In this example,
the inputs measured by the 928A may be either voltage
or current signals.
SB is delayed from SA by 60 degrees, or approxi-
mately 2.8 milliseconds in time at 60 Hz. The phase
is therefore referred to as lagging and given a negative
sign.
If you prefer to see a lagging signal given a positive
sign, then you should configure this in Phase Prefer-
ences in the Main Menu. See page 16, under Phase
Preferences.
Example from the figure above: Suppose you are
monitoring two signals, with a voltage connected at
Channel A voltage terminals and a current at Channel
B current input terminal. Then, the current would be
lagging the voltage by 60 degrees.
For additional details on phase conventions, please
see page 99, Appendix C – Phase Conventions.
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