Extensometers

An extensometer is a device used to measure mechanical deformation (elongation or compression) of a material or structure when it is subjected to stress. Extensometers are widely used in civil, geotechnical, and structural engineering to assess the integrity of structures such as dams, bridges, tunnels, and slopes, and to monitor how deformations evolve over time.

Among the main types of extensometers are:

• Multibase borehole extensometers: commonly used in geotechnical applications, these instruments are installed in boreholes drilled into soil or rock to measure radial deformation or internal settlement. By taking measurements at multiple depths, they provide valuable data on stress distribution and subsurface stability.
• Displacement sensors: used to measure relative movement between two points of a structure. They are ideal for monitoring crack widths, joint openings, or differential settlement. Displacement sensors may use mechanical contact methods or non-contact technologies such as lasers or optical systems.

These instruments, often used together in monitoring systems, provide a comprehensive view of deformation behavior in structures and the ground, supporting early detection of potential failures and enhancing safety in critical infrastructures.