Keithley 6430 User Manual

Ohms Measurements 4-3
Ohms measurement methods
There are two methods to measure ohms: auto ohms and manual ohms. When using auto
ohms, the SourceMeter operates as a conventional constant current source ohmmeter. To use
this method, simply select an ohms measurement range (or use autorange), and take the reading
from the display. When using auto ohms, the default test current varies with the ohms range, as
summarized in Table 4-1.
NOTE You cannot change the test current in the auto ohms mode. If you attempt to change
the source current in auto ohms, the SourceMeter will display an error message.
With the manual ohms mode you can select either source V or source I to make ohms mea-
surements, and the unit will automatically compute the resistance reading using the V/I mea-
surement method. After configuring the desired source and selecting a voltage or current
measuring range, select the Ω measurement method to display the calculated V/I ohms reading.
NOTE To achieve optimum accuracy, the SourceMeter measures both V and I and uses
these values in ohms calculations (with source readback enabled). The measured
source value is more accurate than the programmed source value. For remote opera-
tion, the user specifies the functions to measure. See the resistance measurement
accuracy specifications in Appendix A for more information.
Table 4-1
Auto ohms default test currents
Auto ohms range* Default test current
020Ω
200Ω
002kΩ
020kΩ
200kΩ
002MΩ
020MΩ
200MΩ
002GΩ
020GΩ
200GΩ
002TΩ
020TΩ
100mA
010mA
001mA
100mA
010mA
001mA
001mA
100nA
010nA
001nA
100pA
010pA
001pA
*200MΩ maximum without PreAmp

Keithley 6430 Specifications

General

Brand	Keithley
Model	6430
Category	Measuring Instruments
Language	English