Keithley 2303, Service Manual, Page: 29 / 104

2-4 Calibration
Figure 2-1
Test resistor connections
Resistor considerations
The test resistors should be characterized using the 4-wire ohms function of the DMM rec-
ommended in Table 2-1 to measure the resistance values. Use the measured resistance values to
calculate the actual currents during the calibration procedures.
NOTE The temperature coefficient and temperature change of the 4
Ω
and 30
Ω
resistors
when passing current at full load must be low enough so that the change in resistance
does not cause incorrect readings as follows:
V
OUT
/
∆
R <25% of Model 2303 amps specification. (V
OUT
is the Model 2303 output
voltage, and
∆
R is the change in resistance caused by heating.)
Front panel calibration
Model 2303 and Model 2303-PJ front panel calibration are covered separately below.
Model 2303 front panel calibration
Use the following procedure to calibrate the Model 2303 from the front panel. Table 2-2 sum-
marizes calibration steps.
NOTE Calibration must be performed in the following sequence, or an error will occur. To
abort calibration and revert to previous calibration constants at any time during the
procedure, press the MENU key.
2303
2303 Sense +
2303 Sense -
2303 Source -
DMM Input HI
DMM Input LO
Test Resistor
深圳德标仪器
135-1095-0799