Ballantine 3207, Инструкция по эксплуатации

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BALLANTINE LABORATORIES, Inc. MODEL 3207 MICRO-OHM METER
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3.7 Continuous Mode Operation
In CONT mode, current is continuously supplied to the sample. This mode is recommended
for making measurements of inductive loads like: transformer winding, coil winding and
motor winding.
3.8 Precautions To Be Taken For Various Types Of Measurement:
Fuses: While measuring the resistance of fuses, the test current must be observed
otherwise the fuse may blow. To avoid this, read section 6.1 `Specifications’. `Test leads
with gold plated Kelvin clips’ are recommended for this measurement.
Bus bars: Disconnect the supply before measurement. `C clamp assembly with 10 meter
long leads is recommended for this measurement.
Small resistors: Do not check the resistor in circuit otherwise you may get erroneous
readings and also damage the instrument. `Test lead with gold plated Kelvin clips’ are
recommended for such measurements.
HV transformers:
Caution
Discharge the inductors before making connections for measurement.
Ensure firm contact during connections, to avoid HV generated Back EMF due to the
interruption of current through the inductance of the winding.
Note
Caution is to be followed especially while measuring transformer-winding resistance, of large
power transformers in the order of 1 MVA and above or in motor windings. When the
inductive resistance under test is adjacent to high voltage (HV) ac generation and/or
transmission equipment, they are likely to pick up noise which may result in unstable
readings. This instrument is specially designed to reject unwanted pick up. In spite of this, if
the display instability is found to be excessive, this is due to the noise present e.g. EMI