Table of Contents
Advertisement
5-38
Delta, Pulse Delta, and Differential Conductance
Measurement units
The fundamental measurement for Differential Conductance is differential voltage
(dV). However, the dV reading can be converted into a differential conductance
(dG), differential resistance (dR), or power (Watts) reading. See
details on selecting
With Ohms (dR) or Siemens (dG) measurement units selected, the reading is cal-
culated as follows:
dR = dV/dI
dG = dI/dV
Power – With Power measurement units selected, power is calculated using
Average Voltage and Average Current. Details on Differential Conductance Power
calculations are provided in Section 5 of the Reference Manual (see "Average
Voltage and Power").
Configuration settings
Differential Conductance settings from the front panel are described as follows.
These parameters are set from the DIFF CONDUCTANCE menu, which is
accessed by pressing the CONFIG key and then the COND key.
The equivalent remote programming commands to configure Differential Conduc-
tance are summarized in
Step – The step size specifies the size increment for each step of the sweep. In
Figure
be larger than the start-stop interval, the step size will be readjusted to provide a
100-point Differential Conductance sweep.
Step is a magnitude and is therefore always set as a positive value. Step can be
set from 0 to 105mA. The default step size is 1µA.
Start – The start level for the sweep applies to the middle step of the first cycle. As
shown in
The start level can be set from -105mA to +105mA. The default start level is -
10µA.
Stop – The stop level for the sweep applies to the middle step of the last cycle. As
shown in
sweep. The stop level can be set from -105mA to +105mA. The default start level
is +10µA.
Delta – The specified Delta is the differential current (dI) for the sweep. It is alter-
nately added to and subtracted from each subsequent step in the sweep. As
shown in
tracted from the even numbered steps. Model 2182/2182A A/D readings are per-
formed at each stepped delta level. Delta is a magnitude and is therefore always
set as a positive value. Delta can be set from 0 to 105mA. The default Delta set-
ting is 1µA.
"Measurement
Table
5-10, the 10µA steps are shown by the dashed line. If the step size is set to
Figure
5-10, the 0µA Start level is actually the second step of the sweep.
Figure
5-10, the 50µA Stop level is actually the second last step of the
Figure
5-10, 10µA is added to the odd numbered steps and then sub-
Return to
Model 6220/6221 User's Manual
units".
5-4.
Section 5 topics
page 5-11
for
Advertisement
Table of Contents
