EA Technology CableData CDC2, Руководство по эксплуатации

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EA Technology CableData Collector Operating Manual 1365/L/01/1
Page 31 of 54
sampling rate provides a better resolution of the waveform being captured; however, this
limits the maximum length of the cable that can be tested.
A lower sampling rate allows longer cables to be tested; however, the high frequency
resolution will be reduced. If the cable length is an estimate, and the length is thought to be
near to a length limit for the sampling rate, it is recommended to choose a slower sampling
rate to ensure that mapping is possible.
The theoretical maximum cable lengths for each sample rate are shown in Table 1.
Sample Rate Maximum Cable Length (m) Maximum Cable Length (Feet)
160MHz 2,800 9,186
80MHz 5,600 18,372
40MHz 11,200 36,745
Table 1
– Theoretical Maximum cable lengths for each sample rate
Caution: If the cable being tested is longer than allowed by the selected sampling rate, then
cable mapping will not be possible from the data set. The maximum cable length is 11,200m.
If this is exceeded then the warning message shown in Figure 37 will be displayed.
Figure 37 - Warning when entering a cable length of over 11,200m
10.4.7 Voltage
The next field, visible in Figure 38, is the
Voltage of the cable under test. Several common
voltages for the UK distribution network are available by default.
Figure 38 - Voltage selection
If the cable under test operates at an unlisted voltage, it is possible to add further options. To
do this, select the
Other…
option at the bottom of the list. The window, shown in Figure 39
will then be displayed, which will allow you to enter a new voltage. Only the numeric value of
the voltage needs adding, as the software automatically adds the unit.