Keithley Interactive SourceMeter 2450 User Manual page 51

Model 2450 Interactive SourceMeter® Instrument User's Manual Section 6: Leakage current and insulation resistance
The following TSP code performs a capacitor leakage measurement by sourcing 20 V and measuring
the resulting leakage current. The Duration Loop trigger model template applies the voltage for 60
seconds and makes measurements at 200 ms intervals. After the duration time, the capacitor is
discharged at 0 V and the output is turned off.
After the code is executed, the measurement results are displayed in the Instrument Console of Test
Script Builder. From the Instrument Console, you can copy the data into a spreadsheet for graphing.
Send the following commands for this example application:
-- Reset the instrument, which also clears the buffer.
reset()
-- Set up the source function.
smu.source.func = smu.FUNC_DC_VOLTAGE
smu.source.ilimit.level = 10e-3
smu.source.level = 20
-- Set up measure function.
smu.measure.func = smu.FUNC_DC_CURRENT
smu.measure.terminals = smu.TERMINALS_REAR
smu.measure.autorange = smu.ON
smu.measure.nplc = 1
-- Turn on the output and initiate readings.
smu.source.output = smu.ON
trigger.model.load("DurationLoop", 60, 0.2)
trigger.model.initiate()
-- Wait for the trigger model to complete.
waitcomplete()
-- Parse index and data into three columns.
print("Rdg #", "Time (s)", "Current (A)")
for i = 1, defbuffer1.n do
print(i, defbuffer1.relativetimestamps[i], defbuffer1[i])
end
-- Discharge the capacitor to 0 V and turn off the output.
smu.source.level = 0
delay(2)
smu.source.output = smu.OFF
The graph in the following figure shows the results of this application. Notice the exponential current
response of the capacitor as it charges up to 20 V over time.
2450-900-01 Rev. C / December 2013 6-7