The system reads the output of extensometers installed in the roof of an underground coal mine and sends this information via the Dupline two wire transmission system to the GEL extensometer roof monitoring system. This allows real time data readings of the extensometer to be transmitted to the surface or local PLC network.

The surface installation could consist of a computer interface to the Dupline underground network. This real time access to the extensometer would allow trending, logging and alarming of underground roof activity.

The system has been designed by Austdac and has approvals for underground use the company said.

Austdac said the system has attracted a lot of interest and four mines are expected to have installations within the next three months.