6240B DC Voltage Current Source/Monitor Operation Manual
9.5.3 How to Calculate Accuracy for Low-Resistance Measurement
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9.5.3
How to Calculate Accuracy for Low-Resistance Measurement
The accuracy for low-resistance measurement is calculated by using the following formulas:
*2:
Full-scale item = (A + Rm
B)/Is
A: Voltage limiter range tolerance
Typical value of full scale item tolerance
Low-resistance measurement
(4-wire connection)
Reading item:
(Current source setting item + Voltage measurement reading item)
Full-scale item:
*2
Voltage limiter range
A
300 mV
10
V
3 V
50
V
15 V
1 mV
Rm: Resistance measured value
B:
Current value tolerance due to current source linearity
3 digits worth (
5 digits worth in the 4 A range)
Is:
Current source setting value
Voltage
source range
Voltage limiter range
A
Rm
B
Is
Tolerance
30 mA
300 mV
10
V
10 m
3
A
10 mA
1 m
300 mA
300 mV
10
V
30
A
100 mA
103
1 A
300 mV
10
V
300
A
1 A
13
30 mA
300 mV
10
V
100 m
3
A
10 mA
1 m
300 mA
300 mV
10
V
30
A
100 mA
130
1 A
300 mV
10
V
300
A
1 A
40
30 mA
300 mV
10
V
1
3
A
10 mA
1.3 m
300 mA
300 mV
10
V
30
A
100 mA
400
1 A
3 V
50
V
300
A
1 A
350
