Output Current Accuracy; Voltage Measurement Accuracy Limits - Keithley SourceMeter 3A 2420 Service Manual

Table 1-4

Voltage measurement accuracy limits

Model 2420 source
and measure range*
*Measure range coupled to source range when simultaneously sourcing and measuring voltage.
**As measured by precision digital multimeter. Use closest possible value, and modify reading limits
accordingly if necessary.

Output current accuracy

Follow the steps below to verify that Model 2420 output current accuracy is within specified
limits. The test involves setting the output current to each full-range value and measuring the
currents with a precision digital multimeter.
10µA to 1A range accuracy
1.
Figure 1-2
Connections for 10 µ A
to 1A range current
verification tests
2.
3.
Source voltage*
200mV 200.000mV
2V 2.00000V
20V 20.0000V
60V 60.0000V
With the power off, connect the digital multimeter to the Model 2420 INPUT/OUTPUT
jacks, as shown in Figure 1-2.
MEAS
EDIT V I
DISPLAY
1
0
TOGGLE
LOCAL REL
POWER
6 7
DIGITS SPEED
Digital Multimeter
Select the multimeter DC current measuring function.
Press the Model 2420 SOURCE I key to source current, and make sure the source output
is turned on.
Model 2420 voltage reading
limits (1 year, 18°C-28°C)
199.676 to 200.324mV
1.99946 to 2.00054V
19.9960 to 20.0040V
59.9880 to 60.0120V
4- WIRE INPUT/
SENSE OUTPUT
HI
75V 5V 75V
PEAK PEAK PEAK

2420 3A SourceMeter
LO
250V
SOURCE
PEAK
Ω
FCTN V I
RANGE
2 3 4 5 EDIT
AUTO
TERMINALS
FILTER LIMIT TRIG SWEEP
ON/OFF
RANGE FRONT/
8 9 +/-
REAR
STORE RECALL CONFIG MENU EXIT ENTER
OUTPUT
Model 2420
Input LO
Performance Verification
Amps
1-11