SIG
L
ENT
96 SDM3055 Digital Multimeter
Application of the Analog Filter
The analog filter of the Multimeter can be used to reduce the influence of the
AC component in DC measurement. Generally the filter may not be required,
but sometimes it can improve the DC measurement. For example, if the
measured DC electrical source has a big AC ripple, the analog filter can
reduce the influence.
The analog filter can’t be used to filter the internal noise of the instrument. 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. The
Multimeter should be cleared under the selected range and reading rate to
decrease the offset when using the analog filter. If you cannot clear the
instrument, the measured results will have errors. For other ranges and
reading rates, the additional error generated by the filter can be omitted.
Table 5- 3 Analog Filter Error in DCV measurement
Range
Reading Rate
Additional Analog Filter Error
200mV
Slow
10μV
Middle
20μV
Fast
20μV
2V
Slow
15μV
Middle
20μV
Fast
20μV
20V
Slow
0.8mV
Middle
1mV
Fast
1mV
Table 5- 4 Analog Filter Error in DCI measurement
Range
Reading Rate
Additional Analog Filter Error
200μA
Slow
0.002% range
Middle
0.005% range
Fast
0.005% range
20mA
，
2A
Slow
0.040% range
Middle
0.060% range
Fast
0.080% range
200mA
Slow
0.004% range
Middle
0.010% range
Fast
0.010% range
10A
Slow
0.008% range
Middle
0.010% range
Fast
0.010% range
