GEO-Instruments Products

The Vibrating Wire Crackmeter is designed to measure displacements across cracks and joints in buildings, bridges, dams, pipelines etc. It can measure in expansion and compression of joints. The sensor functions by changing the tension in a spring which is in turn connected to a vibrating wire at one end and a connecting rod at the other. The rod is fully sealed with 'O' rings to prevent water ingress into the sensor.

The Geo-Instruments crackmeter provides a proven long term monitoring solution for many structural applications requiring discrete relative displacement measurements in near real time. They are easily installed and provide a direct method to detect differential movement on structures. Crackmeters may be integrated with our WiSe data logging system, or with standard CSI type loggers. Please see separate datasheets for loggers.

The Scratch Pad Crackmeter/Recorder is ideal for monitoring thermal movement of cracks/ joints, settlement of buildings, slab adjustments during jacking operations, behavior of structural members under loads/unloading, deflection of rail tracks, and changes in existing conditions.

The Vibrating Wire Jointmeter is specially designed for measuring the relative displacement of two adjacent surfaces in three orthogonal directions. Typical applications include monitoring of movement at constructions joints in concrete dams, tunnels and tanks or masonry structures. The Vibrating Wire Perimetric Jointmeter has been designed specifically for use on concrete-faced dams to measure movement across the perimetric joint between the concrete face and plinth, either perpendicular or parallel to the perimetric joint, in the plane of the concrete face or normal to it.

The Mechanical Triaxial Jointmeter is designed to measure movement in three axes across any joint, be it a construction joint in concrete or a tension crack in rock. Stainless Steel bushes orientated in three directions, horizontal, vertical and lateral with respect to the concrete or rock surface, accept either a digital or dial depth gauge, which precisely measures the distance to corresponding stainless steel anvils. Comparison of readings with base data indicates the direction and magnitude of movement.

The Linear Potentiometer Crackmeter is a robust, high resolution and accuracy instrument designed to measure displacements across cracks and joints in buildings, bridges, dams, pipelines etc. It can measure in expansion and contraction. The rugged, waterproof potentiometer is anchored to the structure to be monitored with grout-in or expansion anchors. A change in distance between the anchors, caused by the crack opening or closing will cause a connecting rod to move within the potentiometer body, changing the potentiometer out put and thus the movement of the crack can be determined.

The Vibrating Wire Embedment Jointmeter is ideal for monitoring movement of joints in mass-concrete structures. Typical applications include Abutments, slabs, foundations, retaining walls, tunnels or shaft linings, arch, gravity and buttress dams. The vibrating wire displacement transducer used for jointmeters consists of a vibrating wire sensing element anchored at one end and connected to a spring loaded push rod at the other end.