Monitoring system - Ni-Cr wires (DELFIN)

Description:

The DELFIN monitoring system, proposed by INPAL Energie, consists of 2 Ni-Cr (Nickel Chromium) alarm wires inside the insulation of the pipes and accessories. The system is based on the quantity of electricity conducted by the insulation. Depending on the amount of moisture of the polyurethane foam, the electrical resistance between the service pipe and the foam decreases. Humidity can be detected by measuring the impedance. Errors are recorded using monitoring units which can transmit the information by modem to a surveillance centre.

The DELFIN system also performs self-diagnostics of faults likely to appear on the network

All parameters can be consulted locally on the device screen or via an RS232 link accessible by modem for remote management.

Design:
The circuit diagram must be designed before implementation to guarantee optimum accuracy and use when taking measurements on the system. Maximum loop length is 1000 m.

Generally, the entire network must be monitored. Future connections, if known, must be taken into account.

When the measurement loop is brought to the monitoring unit via a cable outside the insulation, we recommend a maximum distance of 500 m.