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4.1.2 Options for direct and inductive signal coupling
4.1.2.1 Direct coupling on cables and pipes
Introduction Direct galvanic coupling is practical for cables which are easily accessible and free of
current. The method of connection is dependent upon the position and nature of the
lines (e.g. insulation, cable conduit, accessibility of the cable ends).
Direct coupling presents a reliable option for selective cable location, as the signal
can be coupled onto a specific cable with virtually no loss.
The following illustration shows an example of direct coupling:
If the lines being located are energised, the following five safety precautions should
be taken before connecting the transmitter:
Five safety precautions
1. Disconnect power
2. Secure against reconnection
3. Check for presence of current
4. Make earth connection and short circuit
5. Cover or block access to adjacent components which are energised
WARNING
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