Embedment Strain Gauge
Geosense® VWS-2100 series vibrating wire embedment strain gauges are designed for direct embedment in concrete.
The strain gauge operates on the principle that a tensioned wire, when plucked, vibrates at its resonant frequency. The square of this frequency is proportional to the strain in the wire.
The gauge consists of two end blocks with a tensioned steel wire between them.
Around the wire is a magnetic coil which when pulsed by a vibrating readout or data logger interface plucks the wire and measures the resultant resonant frequency of vibration.
Deformation within the concrete will cause the two end blocks will move relative to each other. The tension in the wire between the blocks will change accordingly thus altering the resonant frequency of the wire.
VWS-2125 can be used within mass concrete with coarse aggregates as it’s heavy duty construction resists bending and the large end flanges provide a high contact area.
Surface Mount Strain Gauge
Geosense® VWS-2000 series vibrating wire surface strain mount gauges are designed for the long term monitoring of steel or concrete structures. Gauges may be attached to steel structures by arc welding or, using alternative end blocks, bonded or grouted into concrete.
The strain gauge operates on the principle that a tensioned wire, when plucked, vibrates at its resonant frequency. The square of this frequency is proportional to the strain in the wire.
The gauge consists of two end blocks with a tensioned steel wire between them. The end blocks can be attached by either arc welding, bonding or groutable anchors to steel or concrete.
Around the wire is a magnetic coil which when pulsed by a vibrating readout or data logger interface plucks the wire and measures the resultant resonant frequency of vibration.
As the steel or concrete surface undergoes strain the end blocks will move relative to each other. The tension in the wire between the blocks will change accordingly thus altering the resonant frequency of the wire.
Spot Weld Strain Gauge
Geosense® VWS-2020 series vibrating wire strain gauges are designed primarily to measure strains on the surface of steel structures but may also be used on other types of material.
The gauge consists of two end blocks with a tensioned steel wire between them. The end blocks are attached to stainless steel tabs which may be attached to steel structures by spot welding or, using alternative end blocks, bonded or grouted.
Precision tensioning is carried out on site using a special tensioning jig and the gauge can be set for compression, tension or at mid point.
The strain gauge operates on the principle that a tensioned wire, when plucked, vibrates at its resonant frequency. The square of this frequency is proportional to the strain in the wire.
Around the wire is a magnetic coil which when pulsed by a vibrating wire readout or data logger interface plucks the wire and measures the resultant resonant frequency of vibration.
As the steel or other surface undergoes strain the end blocks will move relative to each other. The tension in the wire between the blocks will change accordingly thus altering the resonant frequency of the wire.
VWS-2020 strain gauges are available in two versions:
- Gauge with integral coil housing
- Gauge only with separate coil housing
Sister Bar/Rebar
Geosense® VWS-4000 series vibrating wire Sister Bars and Rebar Strain Meters are designed to be embedded in concrete to measure strains due to imposed loads.
SISTER BAR
The VWS-4000 Sister Bar is installed by tying it alongside an existing length of rebar within the cage. Available in two diameters: 12 and 16mm.
REBAR STRAIN METER
The VWS-4001 Rebar Strain Meter is installed by welding it into the existing rebar cage at a location within the structure where loads can be accurately passed from the concrete into the gauge. Available in various diameters to match the size of the rebar cage into which it is to be welded.
Strand Anchor Strain Gauge
Geosense® VWS-2800 vibrating wire strain gauge is designed for the monitoring of strain along stranded anchors.
The gauge is housed within a robust cover to de-bond it from the surrounding grout and the specially-designed mounting blocks ensure the strain is transferred from the strand to the gauge. The low profile design means that multiple sensors can be installed along the bonded length of strand anchors.
The strain gauge operates on the principle that a tensioned wire, when plucked, vibrates at its resonant frequency. The square of this frequency is proportional to the strain in the wire.
The gauge consists of two end blocks with a tensioned steel wire between them. The end blocks can be attached by either arc welding, bonding or groutable anchors to steel or concrete.
Around the wire is a magnetic coil which, when pulsed by a vibrating readout or data logger interface, plucks the wire and measures the resultant resonant frequency of vibration. As the steel undergoes strain the end blocks will move relative to each other. The tension in the wire between the blocks will change accordingly thus altering the resonant frequency of the wire.