The Bassett Convergence System is designed to measure delta X and delta Z deformations of structures, in near real time.

Primarily used in tunnels, particularly those such as illustrated below where clearances are extremely small, the system is robust, simple and proven.

The Soil Instruments Bassett convergence system uses pairs of solid state servo sensors arranged within short and long arms to provide delta x and delta z data in mm of a tunnel or other structure.

The system can be supplied complete with datalogger and BCWin Data management software to display data both as a graphical representation of the tunnel and with X & Z graphs for each point. Using Argus or I-Site monitoring software alarm functionality can be built into the BCS system.

The Soil Instruments Bassett Convergence System is the only system officially authorised and endorsed by Dr Richard Bassett it's inventor. A paper has been published on the system by the Institution of Civil Engineers in London, who awarded their Halcrow prize to the authors. This paper describes the system in detail and is available from Soil Instruments.