CSG has introduced with the DMS® system the "in-place multiparametric in column" monitoring that allows to completely investigate the entire borehole and therefore to continuously, simultaneously and contextually detect the variations of displacements, water table, temperature, acceleration , etc., within the same borehole, offering a large amount of information in real time and remotely unusual for traditional instruments.

The advantages deriving from this new method of monitoring are both methodological and technical-operational. From the methodological point of view the possibility to monitor more parameters within the same borehole offers a greater correlability between the various geo-indicators. From a technical-operational point of view, a modular system, conformed according to the characteristics of the soil/rock mass to be monitored, offers the advantage of having all the necessary information for the entire vertical of investigation thus allowing a global vision of the problem particularly useful both in phenomena modeling both in the early warning phases management.

Reliability is certainly the essential requirement that a column monitoring system must have. The poor reliability of a monitoring system makes the monitoring itself useless, even potentially harmful, because it creates uncertainty about the parameters or, even worse, generate incorrect and/or unreliable parameters without having full awareness of them. A geotechnical monitoring instrument must allow the acquisition of data without altering the size of the value that is measuring (conformity), must possess the ability to provide measurements of the same size with different instruments (redundancy) and the ability to measure different quantities to describe the phenomenon (consistency).

Regarding reliability, the DMS instrumentation is equipped not only with quality sensors, optimized for the various uses with dedicated production line (SLIDE, SLOPE, ROCK, ...) but also with a particularly robust mechanical structure, able to ensure a high level of protection of the electronics and power supply and data transmission cables, equipped with special devices for the automatic centering of the various modules of the column inside the borehole and special packers that, conveniently positioned, allow an effective separation of the water tables. Last but not least, hardware and softwares contribuite to high reliability with self-diagnostic and self-test procedures that can be managed remotely.

The high reliability also derives from the DMS® mechanical strength. The robustness is particularly important to withstand the deformations induced by the failure kinematisms and to allow the extraction of the instrumentation from the borehole. The extractability is particularly important not only in order to recover the devices to reposition them in another site at the end of the monitoring period, but also to carry out any maintenance operations with the replacement of elements directly in line extracting part or all of the column. The impossibility of extracting the instrumentation from the borehole would not only prevent the repairing of the instruments and, therefore, the resumption of the monitoring activity, but inevitably would also determine the loss of the borehole itself with further cost increase.

DMS columns are made through the connection of rigid stainless steel tubular elements alternated with high resistance reinforced rubber joints. Sensors and control electronics are contained entirely within the tubular mechanical structure, while the power and data transmission cables are positioned inside the joints so as to be particularly protected against the external environment. DMS columns are able to withstand even very high tensile stresses (up to 50 kN), thus allowing monitoring even under severe deformation conditions, as well as extractions and repositioning of the columns over time.

The continuous acquisition of data is an essential requirement to correctly understand the investigated phenomenon and directly manage the onset of any alert levels. Discontinuous monitoring is scarcely effective and limiting because it already intrinsically requires subjective interpretations of data with the risk of not correctly detecting critical issues and with the risk of underestimating or overestimating events.

This requirement should be understood not so much in the intrinsic aspect of the instrument as in the management aspect which, in particular, includes the installation, connection, transmission and processing of data and alarms management.

The DMS instrumentation is easy to install and removable, the connection between the sensors and the control unit is intuitive and immediate, the data transmission is redundant, the data processing is simple with effective and immediate visualization and automatic graphic processing. The system also allows direct alerting based on threshold values (which can also be configured remotely) minimizing false alarms and the time elapsed between the occurrence of the criticality and the issuing of the warning.

This requirement brings together the others (reliability, robustness, continuous data acquisition, simplicity) as a whole, it concerns in particular the functionality of the system and it is the final result of a good planning of the monitoring system. The possibility to monitor several parameters within the same borehole at the same time allows a perfect correlation between the measured quantities and, at the same time, reduces the costs (drilling of one instead of several boreholes, installation of one instead several instruments and data acquisition systems, etc.).

It is possible to recover and reposition the DMS systems, moreover, thanks to the modularity, the columns can be split (with generation of several columns from the original one) or assembled (with generation of a single column starting from two or more columns) according to the new monitoring needs.