RIGOL DM3068 User Manual
Page 155
RIGOL
User’s Guide for DM3068
6-9
Measuring Characteristics
True RMS AC Voltage
Measurement Method
AC-coupled True-RMS -- measure the ac component of input with up to 400 V DC bias on any range.
Crest Factor
≤ 5 at full range
Input Impedance
1 MΩ ± 2%, in parallel with <150 pF capacitance on any range
Input Protection
750 V rms on all ranges
AC Filter Bandwidth
Slow: 3 Hz – 300 kHz
Medium: 20 Hz – 300 kHz
Fast: 200 Hz – 300 kHz
CMRR (common mode
rejection ratio)
70 dB, for the 1 kΩ unbalance in LO lead, <60 Hz common mode signal frequency, ±500 VDC peak maximum.
True RMS AC Current
Measurement Method
Direct coupled to the fuse and shunt; AC-coupled True RMS measurement (measure the AC component).
Crest Factor
≤ 3 at full range
Max. Input
DC + AC current peak value <300% of range. Current with DC current component <10 A rms.
Shunt Resistor
100 Ω for 200 uA, 2 mA
1 Ω for 20 mA , 200 mA
0.01 Ω for 2 A, 10 A
Input Protection
Externally accessible 500 mA, 250 V high speed fuse at the rear panel for 200 uA, 2 mA, 20 mA and 200 mA ranges.
Internal 10 A, 250 V high speed fuse for 2 A and 10 A ranges.
Settling Time Considerations
The default measurement delay of the multimeter can ensure the correctness of the first readings of most of the measurements. Make sure the RC circuit of
input terminal has been fully settled (about 1 s) before accurate measurement.