In-Place Extensometer (IPX)

Overview

The Osprey Measurement Systems In-Place Extensometer is a magnetic-field sensitive probe designed for use in conjunction with standard magnetic extensometer installations. The system automates the monitoring of magnetic extensometers to provide real time data.

The system comprises a stainless-steel bottom and top support, a continuous GRP support rod, and one or more in-place extensometer sensors, cable and a data logger. The sensors are secured onto the support rod using four grub screws. Each sensor is connected to the adjacent sensor by a four-core cable making up an RS-485 serial bus.

Key Features

• Automated Monitoring: Real-time data collection from magnetic extensometers

• High Precision:Sub-millimetric measurements for confident decision making

• Robust Construction: Stainless-steel body with continuous GRP support rod

• RS-485 Serial Bus: Reliable digital communication

• Flexible Configuration: Up to 50 sensors can be installed at user defined depths

• Adaptable: Extend or shorten to match construction works

• Compatible: Works with most magnetic targets and geotechnical data loggers

Applications

The In-Place Extensometer is optimised for use in standard borehole magnetic extensometer installations, including the common requirement to extend or shorten installations.

The versatility and adaptability of the the In-Place Extensometer makes it the ideal solution for monitoring settlement* or* heave where it's needed most - at the centre of construction works where changes are happening on a daily basis. 

High measurement precision coupled with a large range means the IPX can be used in soft soils experiencing large amounts of deformation, or in rock where sub-millimetric accuracy is required. 

The ability to adapt the system on site allows targeting of stratigraphic boundaries where specific strata are being monitored. Alternatively the system allows high sensor density where displacement distribution and permeation of stress relief is the primary concern. 

Applications include:

• Embankments

• Cuttings

• Stockpiles

• Deep excavations

• Tunnel subsidence from surface

• Convergence and subsidence monitored from within a tunnel

• Slopes

• Deep foundations

Limitations

Standards and References

The IPX system is designed in accordance with:

• ISO 18674-1:2015 - Geotechnical investigation and testing – Geotechnical monitoring by field instrumentation – Part 1: General rules

• ISO 18674-2:2016 - Geotechnical investigation and testing – Geotechnical monitoring by field instrumentation – Part 2: Measurement of displacements along a line: Extensometers