Keithley 2790, Reference Manual

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17-2 Model 2790 SourceMeter
®
Switch System Reference Manual
Introduction
Use the procedures in this section to calibrate the Model 2790. Calibration procedures
include:
• Comprehensive calibration: Usually the only calibration required in the field.
• Manufacturing calibration: Usually only performed at the factory (unless the unit
has been repaired).
• Model 7751, 7752, and 7753 calibration: Covers calibration procedures specific to
the Model 7751, 7752, and 7753 modules.
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The information in this section is intended only for qualified service
personnel. Do not attempt these procedures unless you are qualified to
do so.
All the procedures require accurate calibration equipment to supply precise DC and AC
voltages, DC and AC currents, and resistance values. Comprehensive calibration can be
performed any time by an operator either from the front panel or by using the SCPI
commands sent either over the IEEE-488 bus or the RS-232 port. DC-only and AC-only
calibration may be performed individually, if desired.
Environmental conditions
Conduct the calibration procedures in a location that has:
• An ambient temperature of 18° to 28°C (65° to 82°F).
• A relative humidity of less than 60% unless otherwise noted.
Warm-up period
Allow the Model 2790 SourceMeter Switch System to warm up for at least two hours
before performing calibration.
If the instrument has been subjected to extreme temperatures (those outside the ranges
stated above), allow extra time for the instrument’s internal temperature to stabilize.
Typically, allow one extra hour to stabilize a unit that is 10°C (18°F) outside the specified
temperature range.
Also, allow the test equipment to warm up for the minimum time specified by the
manufacturer.
Line power
The Model 2790 requires a line voltage of 100V/120V/220V/240V, +10%, -5% and a line
frequency of 50 or 60Hz. Note that the line frequency is automatically sensed at power-up,
but the line voltage must be manually set to either 100V/120V or 220V/240V as described
in
Section 18 .