IM 2769-10E
―
11
―
5.3.3 Calibration of Standard Resistor
(R
1
to R
5,
and 2771 standard resistor)
Based on a four-terminal resistor comprising a pair of current terminals C
2
and C
2S
,
and a pair of potential terminals P
2S
and P
1S
(same as C
2
) as shown in Fig. 5.1,
measure R
1
to R
5
by the double bridge at an accuracy of higher than 0.1%.
Through this operation, obtain the calibrated resistance values of R
1
to R
5
.
Then, calibrate the 2771 standard resistor in the same way.
In this case, the current value should be 1/3 the value indicated on the "MULTIPLY" jacks.
For this calibration, use of the 2752 precision double bridge is recommended.
5.3.4 Calibration of Measuring Arm Dial
Connect a calibrated resistor 1000 Ω as an external resistor and then
connect a variable standard resistor (10 Ω to 110 Ω) whose accuracy is 0.1% or better,
to the Rx arm in the ×10 range, and measure its resistance.
The calibrated value is obtained as follows:
=
Calibrated value of
measuring arm dial
100 ×
Resistance value of
standard resistor 1000
Ω
Resistance value of
variable standard resistor
Potential
leads
Current
leads
Plug
R
1
to R
5
C
2S
P
2S
P
1S
C
2
Fig. 5.1 Calibration of Built-in Standard Resistors
