Keithley 6487, Справочное руководство

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3-12 Measurements and Sourcing Voltage Model 6487 Reference Manual
Procedure
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Always turn off the Model 6487 power before changing voltage source
connections to avoid a possible shock hazard.
Perform the following steps to measure resistance:
Step 1. Set up voltage source
Press either of the V-SOURCE adjustment keys, then use a manual RANGE key to set the
voltage source range. Set the voltage and current limit to the desired values using the cur-
sor and RANGE keys.
Step 2. Perform zero correction
To achieve optimum accuracy for high resistance measurements, it is recommended that
you zero correct the picoammeter before enabling the ohms function. To do so, make sure
that zero check and the 2nA range are selected, then press the REL key to perform zero
correction. The MON annunciator will be on when zero correct is enabled.
Step 3. Select a manual current range or enable auto range
Use the manual RANGE keys to select a manual measurement range or press AUTO to
enable auto range. When using manual ranging, choose an appropriate value based on the
voltage source setting and the expected measured resistance: I = V/R.
Step 4. Connect the resistance to be measured to the picoammeter
Basic connections for ohms measurements are shown in Figure 3-3 . Note that both the
picoammeter INPUT and the V-SOURCE OUTPUT jacks are connected to the resistance
under test.
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A safety shield is advisable whenever measurements are being made
with voltages over 30V DC. Connections for the safety shield are
shown in
Figure 3-3 . The metal safety shield must completely surround
the noise shield or floating test circuit and it must be connected to
safety earth ground using #18 AWG or larger wire.
Step 5. Select ohms function
Press the I|¾ key to make sure the ohms function is selected.
Step 6. Turn on voltage source
Press the OPER key to turn on the voltage source output. The VOLTAGE SOURCE
OPERATE indicator will turn on.