Section 4
08 November 2022
2 November, 2016
4-3
Meas.
No.
R
X
Resistor
R
s
Resistor
Excitation
Current
Reversal
Rate
Meas.
Mode
Tests 1 – 13 for all 6622A T-Option bridges.
1
10
Ω
10
Ω
3.16 mA
20 sec
Normal
2
10
Ω
10
Ω
3.16 mA
20 sec
Normal
3
100
Ω
100
Ω
1.0 mA
20 sec
Normal
4
100
Ω
100
Ω
1.0 mA
20 sec
Normal
5
1 k
Ω
1 k
Ω
0.316 mA
20 sec
Normal
6
1 k
Ω
1 k
Ω
0.316 mA
20 sec
Normal
7
25
Ω
10
Ω
2.0 mA
20 sec
Normal
8
100
Ω
25
Ω
0.5 mA
20 sec
Normal
9
100
Ω
10
Ω
0.5 mA
20 sec
Normal
10
400
Ω
100
Ω
0.5 mA
20 sec
Normal
11
1 k
Ω
400
Ω
0.2 mA
20 sec
Normal
12
1 k
Ω
100
Ω
0.2 mA
20 sec
Normal
13
1 k
Ω
10
Ω
0.2 mA
20 sec
Normal
3. For each resistor pair, calculate and report the interchange closure error. For example, if
the Rx:Rs ratio of the first measurement is R
a
and the Rx:Rs ratio of the second
measurement, where the two resistors are exchanged with one another, is R
b
, then the
interchange error e
i
in parts per 10
6
of the nominal ratio is:
e
i
= (1/2) x
(R
a
x R
b
) -1
x 10
6
4. The maximum allowable interchange closure errors (parts per 10
6
) for the following
resistor pairs are:
Resistor Resistor
Interchange Closure Error
6622A
6622A-XP
6622A-XR
6622A-XPR 6622A-HV
10
Ω
10
Ω
0.2
0.1
0.2
0.1
0.1
100
Ω
100
Ω
0.2
0.1
0.2
0.1
0.1
1 k
Ω
1 k
Ω
0.2
0.1
0.2
0.1
0.1
5. For the first 10:1 ladder up closure error (100:10), the 10:1 ratio must agree to within
the specification of the nominal ratio for either directly measuring the 10:1 ratio, or
calculating the ratio from the product of the 10:2.5 ratio and the 2.5:1 ratio, as
follows:
e
i
= (1/3) x
R
a
– (R
b
x R
c
)
/R
a
x 10
6
Summary of Contents for 6622A Series
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Page 23: ...Section 3 08 November 2022 2 November 2016 3 14 Figure 3 4 Rear Panel Connections PRT SPRT...
