User`s guide

RIGOL
User’s Guide for DM3058/DM3058E
5-5
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
Range
Reading Rate
Additional Analog Filter Error
200mV Slow 10μV
Medium 20μV
Fast 20μV
2V
Slow
15μV
Medium
20μV
Fast 20μV
20V Slow 0.8mV
Medium 1mV
Fast 1mV
Table 5-4 Analog Filter Error in DCI measurement
Range
Reading Rate
Additional Analog Filter Error
200μA
Slow
0.002% range
Medium 0.005% range
Fast 0.005% range
20mA, 2A Slow 0.040% range
Medium 0.060% range
Fast
0.080% range
200mA
Slow
0.004% range
Medium 0.010% range
Fast 0.010% range
10A Slow 0.008% range
Medium 0.010% range
Fast
0.010% range