Keithley SourceMeter 3A 2420, Service Manual

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Calibration 2-17
Remote calibration procedure
Step 1: Prepare the Model 2420 for calibration
1. Connect the Model 2420 to the controller IEEE-488 interface or RS-232 port using a
shielded interface cable.
2. Turn on the Model 2420 and the test equipment, and allow them to warm up for at least
one hour before performing calibration.
3. If you are using the IEEE-488 interface, make sure the primary address of the Model 2420
is the same as the address specified in the program you will be using to send commands.
(Use the MENU key and the COMMUNICATION menu to access the IEEE-488 address.)
Step 2: Voltage calibration
1. Connect the Model 2420 to the digital multimeter (see Figure 2-1), and select the multi-
meter DC volts function.
2. Send the commands summarized in Table 2-8 in the order listed to initialize voltage cal-
ibration. (When the :CAL:PROT:CODE command is sent, the instrument will assume
the operating states listed in Table 2-2.)
3. Perform the range calibration steps listed in Table 2-9 for all ranges. For each range:
• Send the :SOUR:VOLT:RANG command to select the source and sense range being
calibrated.. For example, for the 2V range, the following command would be sent
:SOUR:VOLT:RANG 2
• Program the source to output the negative full-range value using the :SOUR:VOLT
command.
For example:
:SOUR:VOLT -2
• Note and record the multimeter reading.
• Use the multimeter reading as the parameter for the :CAL:PROT:SOUR and
• :CAL:PROT:SENS commands. For example, a typical value for the 2V range would be:
:CAL:PROT:SOUR -1.998
:CAL:PROT:SENS -1.998
• Program the voltage source for 0V output using the :SOUR:VOLT 0.0 command.
• Note the multimeter reading.
• Send the source and sense calibration commands using the multimeter reading for the
parameter. For example:
:CAL:PROT:SOUR 1E-3
:CAL:PROT:SENS 1E-3
• Set the source to the positive full-range value using the :SOUR:VOLT command. For
example:
:SOUR:VOLT 2