Fluke 5730A - Page 36

5730A
Operators Manual
1-22
Current Derating Factors
Nominal Value
(Ω)
Value of Derating Factor K for Over or Under Current
Two-Wire Comp
I < IL
[1]
Four-Wire
I < IL
[1]
Four-Wire
IU < I < IMAX
[2]
SHORT
1
1.9
10
19
100
190
1 k
1.9 k
10 k
19 k
100 k
190 k
1 M
1.9 M
10 M
19 M
100 M
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.4
5000
5000
⎯
⎯
⎯
⎯
⎯
⎯
0.3
300
160
30
16
3.5
2.5
0.4
0.4
50
50
7.5
4.0
1.0
0.53
0.2
0.53
0.1
⎯
4 x10
-5
1.5 x 10
-4
1.6 x 10
-3
3 x 10
-3
1 x 10
-2
1.9 x 10
-2
0.1
0.19
2.0
3.8
2 x 10
-5
3.8 x 10
-5
1.5 x 10
-4
2.9 x 10
-4
1 x 10
-3
1.9 x 10
-3
⎯
Notes:
1. For I < I L, errors occur due to thermally generated voltages within the 5730A. Use the following equation to determine the error,
and add this error to the corresponding specifications.
Error = K(I
L
- I)/( I
L
x I)
Where: Error is in mΩ for all two-wire comp values and four-wire short, and in ppm for the remaining four-wire values.
K is the constant from the above table;
I and IL are expressed in mA for short to 1.9 kΩ;
I and IL are expressed in μA for 10 kΩ to 100 MΩ
2. For I
U
< I < I
MAX
errors occur due to self-heating of the resistors in the calibrator. Use the following equation to determine the error
in ppm and add this error to the corresponding specifications.
Error in ppm = K(I
2
-I
U
2
)
Where: K is the constant from the above table;
I and I
U
are expressed in mA for short to 19 kΩ;
I and I
U
are expressed in μA for 100 kΩ to 100 MΩ