Line synchronization is not available for the AC functions (ACV, ACI, FREQ, or PERIOD). Line
synchronization can be enabled for any DC function and any NPLC measurement, increasing NMRR
and CMRR.
See dmm.linesync (on page 11-195) in the Reference Manual for remote programming information.
Figure 102: Line cycle synchronization
4-Wire Ohms are sensitive to 50 / 60Hz power line noise, due to cabling and Model 3700A switch
card loop area.
Figure 103: 4-Wire Line Synchronization Block Diagram
Traditional DMM 4-wire measurements are made in two phases, S HI and S LO. If the dmm.nplc is
set to 1 or a multiple of the power line, theoretically, the average AC noise is 0. Refer to the 4W-Rdg
calculation (http://www.maxim-ic.com/appnotes.cfm/appnote_number/1041/).
To Next Page
Loading...
