Application of the Analog Filter 
The analog filter of DM3058/DM3058E can be used to reduce the influence of the 
AC component in DC measurement. For most measurement, the filter may not 
require, but sometimes it can improve the DC measurement. For instance, if the DC 
electrical source to be measured has a big AC ripple, it can be reduced by the 
analog filter. 
 
The analog filter cannot be used to filter the internal noise of the multimeter. It has 
no use in DCI opening measurement, DCV short measurement or in measurement 
of the output from a precise DC calibration instrument, on the contrary, it may lead 
in additional noise and a bigger reading offset. To reduce the offset, the multimeter 
should be cleared under the selected range and reading rate when using the 
analog filter. If you cannot clear the multimeter, the measured results will have 
errors as shown in table 5-3 and 5-4. For other ranges and reading rates, the 
additional error generated the filter can be omitted. 
Table 5-3 Analog Filter Error in DCV measurement