Suomen Malmi Ltd rock mechanics carry out in-situ rock stress measurements. For long-term monitoring, sensors and an automatic monitoring system are installed in the bedrock. Elkome delivered to Suomen Malmi Ltd data loggers and measurement device enclosures related to the system.
Monitoring system hundreds of metres deep
Suomen Malmi Ltd has delivered automatic bedrock monitoring systems for example for the Olkiluoto spent nuclear fuel repository site and for tunnel building sites for the expansion of the Helsinki metro. Sensors and the measuring system are installed near the monitoring target. The installation place is often underground, up to hundreds of metres deep.
The measuring system consists of a three point pole extensometer and a data logger based data collection system. The anchors of the pole extensometer are soldered in predefined depths in a hole in the rock made by drilling. Movements in the rock are thus relayed to the reference level on the surface of the rock, which is compared to the starting figure values. The system is used to monitor unexpected changes taking place in the rock.
Data loggers in an IP66 protected device enclosure
Elkome has delivered to Suomen Malmi Ltd data collection systems related to the monitoring system. Data loggers were installed in an IP66 protected device enclosure made of stainless steel. In addition to the data loggers, the device enclosure includes channel expansion units thanks to which it is easy to expand the system depending on the scale of the target of monitoring. Protected feed-throughs for sensor cabling were installed at the bottom of the device enclosure.