Home > Our Technologies > LSI-Lastem


LSI LASTEM is an environmental instrumentation and monitoring system manufacturer, dedicated to advanced, high quality environmental monitoring solutions, including sensors, data-loggers, software and installation and mounting accessories. Ramjack has partnered with LSI LASTEM for its high quality sensors and its advanced tailings dam monitoring technology, G.Re.T.A.

Permanent Geoelectric Monitoring

LSI LASTEM has engineered an innovative solution for permanent geoelectric monitoring of soil conditions. Their flagship geo-resistivity instrumentation system, G.Re.T.A. (which stands for Geo Resistivimeter for Time lapse Analysis), measures the alteration of the soil’s resistivity profile over time, allowing the analysis of water content, the presence of cavities and other anomalies deep into the soil.

Electrical Resistivity Tomography (ERT) uses electrodes to create an electric field in the ground that measures soil resistivity values. Building a resistivity profile of earthen structures – like tailings dams – allows for time lapse analysis of the inherent structure and characteristics of the soil for improved safety – both for the environment and for personnel. Coupling the holistic G.Re.T.A. monitoring system with sensors like pressure cells, extensometers and piezometers creates a comprehensive monitoring system for all earthen structures.



Off-the-shelf, easy to install soil monitoring solution;


Calculates soil % water content along the entire monitored profile;


Remote sensing, with data visualisations and configurations via Cloud software;


Automatic, configurable alarm messages when thresholds are reached;


Deployable as an energy autonomous system in challenging environments;


Interoperable with other real-time monitoring solutions and instruments.

G.Re.T.A. is an innovative solution for Permanent Geoelectric Monitoring of soil conditions on a large scale.

The industrialised hardware is easy to install, and an optimal solution for geoelectrical monitoring.

This instrument measures the soil’s resistivity profile over time, monitoring changes in water content, presence of pollutants, cavities and other anomalies.

Multielectrode Electric Tomography (ERT) uses electrodes inserted in the soil to monitor and measure the voltage. The resulting resistivity value derived from the voltage measurements gives insight into the characteristics of the soil, and allows operations to monitor and act on any changes, in real-time. 

  • Number of electrodes: 48
  • Distance between the electrodes: up to 3 m
  • Measured profile lenght: up to 141 m
  • Max measured profile depth: upto 22,5 m
  • Measurement configuration: Wenner
  • Power supply: solar panel or electric grid
  • Modem or Router for automatic data transmission
  • Remote control and programming via LSI LASTEM Cloud
  • Alarm management based on pre-defined thresholds


  • Measurement and communication Unit
  • Energy supply Unit
  • 48 electrodes cables in anti-rodent material
  • Meteorological sensor integration enabled

The Heart of G.Re.T.A.

Energy efficiency
All components are designed for the lowest possible energy consumption.
Filtration of any disturbing signals
The G.Re.T.A. system recognises and excludesany disturbing signals present in the ground.
Modular architecture
Each specific function (current injection voltage measurement, signal switching, processing and data transmission) is implemented as an independent module, streamlining maintenance activities.

About the company

Since 1972 LSI LASTEM, from its headquarters in Milan (Italy), has been designing, manufacturing, and marketing a complete range of high-quality systems for environmental monitoring.

LSI LASTEM instrumentation is intended for numerous applications for portable and fixed monitoring of both indoor and outdoor environments, always guaranteeing the highest accuracy and reliability of measurements.

At RAMJACK Technology Solutions, we offer solutions from LSI LASTEM to clients in Africa, Europe, the Middle East and Latin America.