Standard Method Resistivity Tests - Keithley 6517B Reference Manual

Section 6: Test sequences Model 6517B Electrometer Reference Manual
This test makes two resistance measurements at two different voltage levels, and calculates the
voltage coefficient. The test circuit is shown in the following figure. The resistor should be placed in a
shielded test fixture that is designed to minimize leakage resistance.
For this test, the first specified voltage (SOURCE V1) is applied to the resistor and, after the specified
delay (DELAY 1), a resistance measurement is made. The second voltage (SOURCE V2) is then
applied and, after the next delay (DELAY 2), a second resistance measurement is made. The Model
6517B then automatically calculates the voltage coefficient and stores it in the buffer. This test is
selected and configured from the CONFigure SEQUENCE menu (DEV-CHAR; RESISTOR).
Figure 72: Resistor Voltage Coefficient Test Circuit

Standard method resistivity tests

This test is used to measure the resistivity (surface or volume) of an insulator sample. When used
with the Keithley Instruments Model 8009 Resistivity Test Fixture, the test conforms to the ASTM D-
257 standard. See Resistance and resistivity measurements (on page 4-18) for test circuit diagrams
and connections to the Model 8009. Refer to the instruction manual for the Model 8009 to install the
insulator sample in the test fixture.
When this test is run, the V-source is initially set to source 0 V for a specified time (PREDISCH time)
to allow any charge to dissipate. The V-source then applies a specified voltage (BIAS V) to the
electrodes of the test fixture for a specified time (BIAS-TIME). This "bias" period allows currents in the
test circuit to stabilize. The V-source then applies the test voltage (MEAS-V) and, after a specified
delay (MEAS-TIME), the Model 6517B measures the resistivity of the sample and stores the reading
in the buffer. Note that the test voltage (MEAS-V) is typically at the same level as the bias voltage
(BIAS V).
The surface resistivity test and the volume resistivity test are selected and configured from the
CONFIGURE SEQUENCE menu (R/RESISTIVITY; NORMAL; SURFACE and VOLUME).
6-6 6517B-901-01 Rev. C / August 2015