AEMC 6255 User Manual page 27

4.3.2. Test Lead Connection
The measurement leads are connected using the four binding posts on the left
side of the front panel as shown in Figure 4-3.
Connect the two red leads to terminals C1 and P1. Connect the two black leads
to terminals C2 and P2.
Any drop in the voltage on the load terminals is measured between the two
"voltage" (V) leads, P1 and P2. The current leads (C1 and C2) can deliver current
from 1mA to 10A.
4.3.3. Very Low Resistance
When measuring very low resistive values in the µΩ range, the presence of stray
DC currents may affect the accuracy of the measurements. These currents can
be present due to a variety of reasons including chemical or thermal EMF in
samples made of dissimilar metals. These EMFs are automatically compensated
for during the measurement process.
The presence of AC interference in the sample under test may cause the
measured value on the display to fluctuate. This interference may become more
noticeable in the presence of strong electric fields. The effects of this interference
may be reduced by twisting the leads around each other.
4.3.4. Meter Readings
When testing resistive samples, the meter reading will stabilize within the first few
hundred milliseconds. On inductive loads (e.g. transformers), the measurement
reading may take from several seconds to a few minutes to stabilize and
depends greatly on the type of equipment and the impedance of the equipment
under test. On very large samples such as utility transformers, 10 to 15 minutes
charging time may be necessary.
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Micro-Ohmmeter Model 6255
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