Isour Open Voltage; Vmeas Open Voltage; Calculated Measurement Open Voltage - Keithley 3700A Series Reference Manual

Series 3700A System Switch/Multimeter Reference Manual

ISOUR open voltage

1 Ω through 1 MΩ ranges: A hardware detector detects an open input lead. The hardware detector
uses a comparator circuit to monitor the voltage on the ohm I
•
For the lower ohms ranges (1 Ω, 10 Ω, and 10 kΩ), open circuit voltage on the ohm I
LEAD
•
For the higher ohms ranges (100 kΩ through 1 MΩ), open circuit voltage on the ohm I
LEAD
When an input lead (HI or LO) is open, as shown, voltage rises to the open-circuit level, then the A/D
will abort in less than 100 µsec and the "Overflow" message is displayed.

VMEAS open voltage

If either Input Sense HI or Sense LO V
less than 100 µs and returns an overflow reading.
Range
1 Ω to100 Ω
1 kΩ to 100 kΩ
1 MΩ

Calculated measurement open voltage

A calculated measurement that exceeds 120 percent of the range returns an overflow reading.
3700AS-901-01 Rev. D/June 2018
terminal is more than 7.1 V.
terminal is more than 12.8 V.
V SHI or SLO high limit open lead
MEAS
detection
> 128 mV
> 1.28 V
> 12.8 V
Figure 115: 4-wire open detector with Series 3700A card
SOUR
is outside the enclosed table voltages, the A/D stops in
MEAS
V
MEAS
detection
< –10 mV
< –100 mV
< –1.0 V
Section 8: Theory of operation
V terminal.
OPEN-HI-LEAD
SOUR VOPEN-HI-
SOUR VOPEN-HI-
SHI or SLO low limit open lead
8-15