Section 4
OM6624CT-3000-5-00
11 May, 2016
4-2
4.3.
PROCEDURE
4.3.1.
Preliminary Connections to the 6624CT-3000
1.
Place the 9230A-10-1 Resistance Standard and the 9230A-300-0.001 Current
Shunt Standard in the Bath and allow stabilizing in temperature at 25.0 C.
2.
Measure, as may be required, the ratio of the DC Current Shunt Standard to that of
the DC Resistance Standard using a 6622A DCC Bridge and 6623A High Current
Range Extender using a test current of 100 A.
3.
Connect the 6624CT-3000 Transformer to the 6623A-3S Controller as shown in
Figure 2-4.
4.
Connect the Current Source output terminal through the window of the 6624CT-
3000 and connect to the 9230A-300-0.001 Current Shunt C2 terminal then
connect the shunt C1 terminal to the Current Source return terminal. See Figure 2-5.
5.
Connect the 9230A-10-1 Resistance Standard current terminals to the 3 A Burden
terminals of the 6623A-3S DC Current Transformer Controller, ensure that a
shorting link is attached to the 150 mA Burden terminals, and ensue that a
Termination Plug is connected to the 'Control' circular connector on the 6623A-3S if
the 66259 Extender Control Unit is not used.
6.
Turn on the 6623A-3S DC Current Transformer Controller, then turn on the Current
Source but do not yet apply any test current.
7.
Observe that the meter indicator on the 6623A-3S initially moves to the right or left
then returns to the centre line within the graduation lines of the meter. A small offset
is satisfactory indication that a balance condition exists.
4.3.2.
Measurement of the Potentials on the Resistors
1.
Set the 6624CT-3000 range switch to the 1000:1 position and apply a test current of
100 A through the window of the 6624CT-3000 and the 9230A-300-0.001
Current Shunt.
2.
Ensure that the 6623A-3S meter indicator remains within the graduation lines of the
meter after any initial transient.
3.
Using the DC Voltmeter measure and record the potentials across both the 9230A-
300-0.001 Current Shunt and 9230A-10-1 Resistance Standard potential
terminals. Ensure that the DC Voltmeter is properly setup for a 100 mV
measurement and sufficient time is allowed for the measurements to settle.
4.
Turn off the current source and reverse the current output cable connections.
5.
Repeat steps 1 to 4 for the reversed test current.
6.
Record the results.
Summary of Contents for 6624CT-3000
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