IM 2769-10E
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7
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4. OPERATING INSTRUCTIONS
4.1 Preparation
(1) Make sure that the INT. BA as well as P
2S
terminals are shorted securely.
Place the BA switch to OFF position, open the Rx terminals.
(2) Set the GA sensitivity dial to CH position.
By doing this, check that the galvanometer driving battery is good.
When the pointer of the galvanometer deflects to the blue zone on the scale,
this shows that the battery is good.
Note: It takes 1 to 2 seconds for stabilized indication.
(3) Set the GA sensitivity dial to G
2
, and check that the galvanometer indication is in the zero position.
If deviated, turn carefully the zero adjusting screw of the galvanometer to obtain a true zero point.
(4) Connect an unknown resistance to the Rx terminal.
(Refer to Fig. 3.4 (b) Connection for Rx terminal.)
4.2 Operation for Measurement
(1) Select a multiplying factor by using the plug, to fit the approximating value of the unknown resistance,
according to Table 4.1.
Rx
MULTIPLY
0.1
to
1.1 mΩ
1
to
11 mΩ
10 to 110 mΩ
0.1
to
1.1 Ω
1
to
11 Ω
10
to
110 Ω
0.0001
0.001
0.01
0.1
1
10
＊
＊
When using 2771
Table 4.1
(2) Turn the BA switch ON.
(3) Set the measuring dial to a position near the center, push the GA button switch momentarily,
and observe the galvanometer.
If the deflection is on the plus (+) side, increase the dial value to obtain zero indication by
repeating the above operation.
When the indication comes near the zero position, push and turn the GA button switch
either clockwise or counterclockwise, to lock the switch.
Then, move the measuring dial to obtain zero indication on the galvanometer.
If the indication is on the minus (-) side in the beginning of this adjustment, reduce the dial value and
obtain zero indication in the same manner as above.
If more sensitivity is required, select G
1
position first, and G
0
.
