Model 2701 User’s Manual
Basic DMM Operation
3-29
Figure 3-11
Ratiometric method to measure ohms (10M
Ω
and 100M
Ω
ranges)
2701
V
MEAS •
R
REF
R
DUT
(I
SOUR •
R
REF
) – V
MEAS
V
MEAS
R
REF
Eq. 1:
R
DUT
Input Hi
Input Lo
A) 2-wire ohms (
Ω2
) measurements (10M
Ω
and 100M
Ω
ranges)
B) 4-wire ohms (
Ω
4) measurements (10M
Ω
and 100M
Ω
ranges)
I
DUT
I
SOUR
= I
REF
+ I
DUT
=
+ V
MEAS
R
DUT
=
V
MEAS •
10M
Ω
(0.7
μ
A
•
10M
Ω
) – V
MEAS
=
Eq. 2:
V
V
MEAS
I
SOUR
0.7uA
R
REF
10M
Ω
I
REF
2701
R
DUT
Input Hi
Input Lo
I
DUT
V
V
MEAS
I
SOUR
0.7uA
R
REF
10M
Ω
I
REF
Example:
Asume: V
MEAS
= 3.4V
3.4V
•
10M
Ω
(0.7
μ
A
•
10M
Ω
) – 3.4V
=
= 9.444M
Ω
R
DUT
Sense Lo
Sense Hi
V
V
LEAD
R
LEAD
R
LEAD
Ω
2 Function
Ω
4 Function
V
DUT
= V
MEAS
- 2(V
LEAD
)
For Eq.1, Eq. 2 and the Example,
V
DUT
is used in place of V
MEAS
.
2701-900-01.book Page 29 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...