TB 9-4931-290-50
(4) Adjust R46 (1 & 10 mV AC) (fig. 1 or 2) for .0100 or .0010 V ac depending on
range switch setting (R).
NOTE
R46 (1 & 10 mV ac) (fig. 1 or 2) affects the 1 mV range as well
as the 10 mV range and should be adjusted for best overall
indication on both ranges.
Figure 1. Model 421A (above S/N 901) adjustments.
6