Keithley 3720-ST User Manual

Section 8: Theory of operation Series 3700A System Switch/Multimeter Reference Manual
8-4 3700AS-901-01 Rev. D/June 2018
Figure 104: 1plc Line Sychronization Block Diagram
For Line Synchronization off and <1 PLC, reading rate increases, but measurement uncertainty and
noise increases due to the Average AC noise during the S HI phase not canceling with the S LO
phase. With line synchronization ON, the S HI and S LO measurement phases are triggered at the
rising edge of the power line zero crossing. This improves reading uncertainty and noise by >30×
while minimal reading rate reduction.
Figure 105: Line Sync Off and On <1plc

Keithley 3720-ST Specifications

General

Brand	Keithley
Model	3720-ST
Category	Multimeter
Language	English