Model 1600A controls, indicators and connectors
(3) The ATS is designed to measure the RMS value of stable AC voltages.
Should the AC indicator light remain illuminated and/or the front panel meter
continuously "hunts" or "slews" when the ATS is operated in either the AUTOMATIC or
MANUAL TRANSFER mode, it is likely that the applied signal is unstable. To judge
the stability of the applied signal, the operator should switch to the manual
balance mode and attempt to null the meter using the MANUAL BALANCE COARSE and/or
FINE controls. If a balance condition cannot be maintained, the applied signal is
fluctuating too rapidly to permit a measurement of specified accuracy to be made.
Under these conditions the measurement should be made in the manual balance mode
and the reduced accuracy (due to the fluctuation of the signal) should be noted.
In AUTO transfer use FAST mode for input signals drifting less than 0.005