The sensors record the elongation of brake rings in guard nets as well as lesser vibrations caused by rock fall happenings. The units are laid out for a maintenance-free operation for several years. Due to autarkic power sources, the sensors require no changes of batteries.
The sensors and the data logger are connected wireless. Data are transmitted in case of changes of the measurement reading and in regular intervals. A permanent presence monitoring is ensured in this way.
The base station contains receiver, storage, evaluation and reporting systems like e.g. relay and GSM/GPRS transmitters for SMS and data transmission. The data logger receives signals of the sensors within a radius of several hundred meters, evaluates them and sends alarm messages out which are transmitted per SMS, email or FTP data to any operator.
It is possible to use the electricity network, batteries or solar panels as power supplies.