Voltage Measurements (Dcv And Acv); Dcv Input Divider; Connections - Keithley 2750 User Manual

3-8 Basic DMM Operation

Voltage measurements (DCV and ACV)

The Model 2750 can make DCV measurements from 0.1µV to 1000V and ACV measure-
ments from 0.1µV to 750V RMS, 1000V peak.
DCV input resistance:
ACV input impedance:

DCV input divider

Normally, the input resistance for the 100mVDC, 1VDC, and 10VDC ranges is >10GΩ ,
while the input resistance of the 100VDC and 1000VDC ranges is 10MΩ . However, the
input resistance for the three lower DCV ranges can also be set to 10MΩ by enabling the
input divider.
With the input resistance lowered, a more stable 0V reading is achieved with an open
input. Also, some external devices (such as a high voltage probe) must be terminated to a
10MΩ load.
The input divider cannot be enabled from the front panel. For remote programming, the
following command controls the input divider:
VOLT:IDIVider <b>

Connections

WARNING
NOTE
100V and 1000V ranges: 10MΩ
100mV, 1V, and 10V ranges: >10GΩ || <400pF or 10MΩ
1MΩ || <100pF
' Enable (ON) or disable (OFF) the DCV input divider.
Even though the Model 2750 can measure up to 1000V peak, the maxi-
mum input to a switching module is less. Exceeding the voltage rating
of a switching module may cause damage and create a safety hazard.
When using the front panel inputs, the INPUTS switch must be in the "F" (out)
position. For switching modules, it must be in the "R" (in) position.
Model 2750 Multimeter/Switch System User's Manual