Keithley SourceMeter 2425, Руководство по обслуживанию

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Model 2425 Service Manual Performance Verification 1-17
4. Verify measurement current accuracy for the 3A range as follows:
• Select the 3A source range.
• Set the Model 2425 source output to the correct 3A value as measured by the digital
multimeter.
• Note the DMM voltage reading, and then calculate the current from the voltage read-
ing and characterized 1
Ω
resistance value as I = V/R, where V is the DMM voltage
reading and R is the characterized resistance value.
• Verify that the Model 2425 current reading is within the 3A limits given in Table 1-
6.
NOTE It may not be possible to set the current source to the specified 3A value. Use the
closest possible setting, and modify reading limits accordingly.
5. Repeat the procedure for a negative 3A current.
6. Repeat the procedure using the rear panel INPUT/OUTPUT jacks. Be sure to select
the rear panel jacks with the front panel TERMINALS key.
Table 1-6
Current measurement accuracy limits
Model 2425 source
and measure range 1 Source current 2
Model 2425 current reading lim-
its (1 year, 18°C to 28°C)
10
μ
A
100
μ
A
1mA
10mA
100mA
1A
3A
10.00000
μ
A
100.000
μ
A
1.00000mA
10.0000mA
100.000mA
1.00000A
3.00000A
9.9966 to 10.0034
μ
A
99.969 to 100.031
μ
A
0.99967 to 1.00033mA
9.9959 to 10.0041mA
99.939 to 100.061mA
0.99928 to 1.00072A
2.99673 to 3.00327A
3
1
Measure range coupled to source range when simultaneously sourcing and measuring current.
2
As measured by precision digital multimeter. Use closest possible value, and modify reading limits
accordingly if necessary.
3
Current calculated as follows: I = V/R, where V is the DMM voltage reading, and R is the
characterized value of the 1
Ω
resistor.