Keithley SourceMeter 3A 2420, Руководство по обслуживанию

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1-6 Performance Verification
Test considerations
When performing the verification procedures:
• Be sure to restore factory front panel defaults as previously outlined.
• Make sure that the test equipment is properly warmed up and connected to the Model
2420 INPUT/OUTPUT jacks. Also be sure that the front panel jacks are selected with
the TERMINALS key.
• Make sure the Model 2420 is set to the correct source range (see below).
• Be sure that the Model 2420 output is turned on before making measurements.
• Be sure the test equipment is set up for the proper function and range.
• Allow the Model 2420 output signal to settle before making a measurement.
• Do not connect test equipment to the Model 2420 through a scanner, multiplexer, or
other switching equipment.
WARNING The maximum common-mode voltage (voltage between LO and chassis
ground) is 250V peak. Exceeding this value may cause a breakdown in in-
sulation, creating a shock hazard.
CAUTION The maximum voltage between INPUT/OUTPUT HI and LO or 4-WIRE
SENSE HI and LO is 75V peak. The maximum voltage between INPUT/
OUTPUT HI and 4-WIRE SENSE HI or between INPUT/OUTPUT LO
and 4-WIRE SENSE LO is 5V. Exceeding these voltage values may result
in instrument damage.
Setting the source range and output value
Before testing each verification point, you must properly set the source range and output val-
ue as outlined below.
1. Press either the SOURCE V or SOURCE I key to select the appropriate source function.
2. Press the EDIT key as required to select the source display field. Note that the cursor will
flash in the source field while its value is being edited.
3. With the cursor in the source display field flashing, set the source range to the lowest pos-
sible range for the value to be sourced using the up or down RANGE key. For example,
you should use the 20V source range to output a 20V source value. With a 20V source
value and the 20V range selected, the source field display will appear as follows:
Vsrc:+20.0000 V
4. With the source field cursor flashing, set the source output to the required value using
either:
• The SOURCE adjustment and left and right arrow keys.
• The numeric keys.
5. Note that the source output value will be updated immediately; you need not press
ENTER when setting the source value.