Keithley 6220 User Manual

Model 6220/6221 Reference Manual Delta, Pulse Delta, and Differential Conductance 5-53
Return to Section 5 topics
Differential Conductance calculations
dV calculations
While the dV calculations for the first six dV readings are shown in Figure 5-14,
the following formula can be used to calculate any dV reading in the test:
Where: X, Y and Z are the three A/D measurements for a dV reading.
n = Reading Number – 1
Example – Calculate the 21st dV reading:
X, Y and Z are the three A/D measurements for the 21st dV reading.
n = Reading Number – 1
= 21 – 1
= 20
Therefore;
The (-1)
n
term in the dV calculation is used for polarity reversal of every other
calculated dV reading. This makes all calculated dV readings in the test the same
polarity.
Simplified dV calculation
The above dV calculation can be simplified as follows:
dV
XY–()
2
------------------
ZY–()
2
------------------+
2
--------------------------------------------
1–()
n
•=
dV
XY–()
2
------------------
ZY–()
2
------------------+
2
--------------------------------------------
1–()
20
•=
XY–()
2
------------------
ZY–()
2
------------------+
2
--------------------------------------------=
dV
XY– ZY–+
2
----------------------------------
2
----------------------------------
1–()
n
•=
dV
X2Y– Z+
4
---------------------------
1–()
n
•=
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Keithley 6220 Specifications

General

Brand	Keithley
Model	6220
Category	Measuring Instruments
Language	English