BASIC OPERATIONS
74
3.
Without leaving the MANUAL mode, to connect the Analyzer to other end of a cable and to
take measurements in the table SET 2.
4.
Analyze results of two measurements. If the received values are identical, test is finished.
5.
If the measurement results are different, determine the exact distance to the detected
heterogeneity, detected closer than the response from the end of the cable.
An example of analysis of test results in MANUAL mode is shown in Fig. 60.
In both tables, the measured distance to the far heterogeneity is 74.6 m. The response level
from this heterogeneity is approximately the same in both measurement cycles (13 dB and 12
dB). This heterogeneity is the end of the cable. So the cable length is 74-75 m.
During the first measurement cycle, heterogeneity was detected at a distance of 53.4 m. The
response level from this heterogeneity exceeds the response level from the end of the cable.
In the second measurement cycle, heterogeneity was detected at a distance of 21.2 m. The
response level from the heterogeneity is very large (104 dB).
This is due to the fact that heterogeneity was detected at a small distance from the connection
point of ST 301. Also, heterogeneity was detected at a distance of 42.8 m with a low response
level (16 dB). Probably, this response is the harmonic of the signal received at a distance of 21.2
m.
Fig.60
Considering the measured line length, the response obtained in the first measurement cycle at
a distance of 53.4 m and in the second measurement cycle at a distance of 21.2 m are responses
from the same heterogeneity.
This conclusion is confirmed by the addition of the measured distances to the heterogeneity in
the first and second cycles: 21.2 m. + 53.4 m. = 74.6 m. (a value equal to the length of the
cable is obtained).
7.4.4. PROCEDURE FOR TESTING OF THE TWO-WIRED CABLE (PAIR OF THE
MULTI-WIRE CABLE)
1. Disconnect the tested cable from the equipment on distant end.
2. Connect a cable to the Analyzer depending on type of the tested cable:
2A (Fig.4), 2C (Fig.5), 3A (Fig.6), 3C (Fig.7), 4A (Fig.8), 5A (Fig.9),
5B (Fig.10), 5C (Fig.11), 6A (Fig.13), 6D (Fig.16)
