Section 4
OM6530-C1-00
19 November, 2019
4-21
I is the unknown current in amperes,
C is the integration capacitance in farads,
V
threshold
is the threshold voltage in volts.
Shunt is 1000 if it has been selected otherwise it is 1. Note: The shunt should be
enabled only when trying to measure currents higher than 10 µA.
The instrument works best if the integration time of the electrometer is between 0.5 s and
5 s however integration times as short as 5.4 ms or as long as 1000 s may be used. The
2700 pF capacitor is the most stable and should always be used if possible.
The following steps can be used to measure current in the manual mode:
1.
Connect the unknown current source.
2.
Select the
<Measure>
function key in the
Main Menu
3.
Select the
<Current>
function key in the
Measure Option Menu
4.
Select the
<Set Up>
function key in the Measure Option Menu to proceed to the Set Up
Menu
5.
Select
<Parameters>
in the Set Up Menu to proceed to the Parameters menu
6.
Using the suggested timing parameters suggested by entries into the Time Diagram of
Figure 4-1 and Table 8-5 to make the appropriate selection of
<Capacitor>
,
<
Threshold>
and
<Shunt>.
7.
Press the front panel menu control key
<PREVIOUS>
to return menu control to the
Set Up menu.
8.
Select the expected test current polarity using the
<Polarity>
function key; (the
polarity convention used is such that for a positive polarity, the centre conductor of the
INPUT connector is at a positive voltage with respect to the inner shield.)
9.
Press the front panel menu control key
<PREVIOUS>
to return menu control to the
Measure Option Menu
.
10.
Select the
<Start>
function key to initiate the measurement cycle.
