Model 2701 User’s Manual
Basic DMM Operation
3-25
Performing offset-compensated ohms measurements
Offset-compensated ohms can only be performed on the
Ω
4 function using the 100
Ω
, 1k
Ω
,
or 10k
Ω
range. Make sure you use 4-wire connections to the DUT (see “Connections,”
page 3-8).
NOTE
Make sure the INPUTS switch is in the correct position. To use front panel
inputs, it must be in the “F” (out) position. For switching modules, it must be in
the “R” (in) position.
1.
If a switching channel is presently closed (displayed), press OPEN to open it.
2.
Select the 4-wire ohms measurement function by pressing
Ω
4. Enable offset
compensated ohms by pressing SHIFT and then OCOMP (OCOMP annunciator
turns on).
3.
Use the RANGE and keys to select the 100
Ω
, 1k
Ω
, or 10k
Ω
range or press
AUTO to enable auto range. If using auto range, offset compensated ohms
measurements will not be performed if the instrument goes to the 100k
Ω
or higher
range.
4.
Perform steps 4 through 8 of the “Standard resistance measurements,” page 3-23,
procedure.
NOTE
The OCOMP annunciator will flash when the instrument is on an invalid range
(100k
Ω
through 100M
Ω
ranges) for offset-compensated ohms. Normal ohms
measurements will instead be performed.
For buffer recall, there is no way to distinguish between a normal ohms reading
and an offset-compensated ohms reading. The OCOMP annunciator (off, on, or
flashing) has no significance for recalled resistance readings that are displayed.
Buffer operation is covered in Section 6.
With offset-compensated ohms enabled, it will be “remembered” by the
Ω
4 func-
tion after you change measurement functions (i.e., DCV). When
Ω
4 is again
selected, offset-compensated ohms will be enabled.
Measurement methods
The Model 2701 uses two methods to measure resistance:
•
Constant-current source method (100
Ω
through 1M
Ω
ranges) – Sources a constant-
current to the DUT. Voltage is measured by the Model 2701and resistance is then
calculated (R = V/I).
•
Ratiometric method (10M
Ω
and 100M
Ω
ranges) – Test current is generated by a
0.7µA source in parallel with a 10M
Ω
reference resistor.
2701-900-01.book Page 25 Wednesday, August 3, 2011 9:43 AM
Summary of Contents for 2701
Page 344: ...12 CommonCommands 2701 900 01 book Page 1 Wednesday August 3 2011 9 43 AM...
Page 366: ...15 SCPIReferenceTables 2701 900 01 book Page 1 Wednesday August 3 2011 9 43 AM...
Page 393: ...A Specifications 2701 900 01 book Page 1 Wednesday August 3 2011 9 43 AM...
Page 399: ...B Model7700ConnectionGuide 2701 900 01 book Page 1 Wednesday August 3 2011 9 43 AM...
Page 410: ...C StatusandErrorMessages 2701 900 01 book Page 1 Wednesday August 3 2011 9 43 AM...
Page 417: ...D SignalProcessing SequenceandDataFlow 2701 900 01 book Page 1 Wednesday August 3 2011 9 43 AM...
Page 430: ...E MeasurementConsiderations 2701 900 01 book Page 1 Wednesday August 3 2011 9 43 AM...
Page 450: ...G KE2700InstrumentDriver Examples 2701 900 01 book Page 1 Wednesday August 3 2011 9 43 AM...