Successful synchronization of two motor generators requires that the voltage outputs of the generators be close to each other, that the two frequencies be identical, and that the voltage waveshapes be in phase.
The two motor generator voltages can be measured by two Laureate AC RMS Voltmeters, which offer selectable voltage ranges up to 600.0V. Or a single AC RMS voltmeter can be multiplexed by using an external toggle switch.
Two frequencies A & B can be measured to six-figure accuracy by a single Laureate Dual Channel Frequency Meter, where each channel monitors a generator. The two AC neutrals must be tied to meter ground. Pressing a front-panel key toggles the reading between the channels. The meter can also display frequency A – frequency B, or frequency A / frequency B without toggling. This meter operating mode with arithmetic functions applied to channels A & B is described in Laureate Ratio Meter page.
Phase angle can be measured using the Laureate Phase Meter.