VW Surface-Mount Strain Gauge
Introduction  |  Spot-Weldable | Surface-Mount | Rebar Strainmeter | Embedment

Applications

Surface-mount strain gauges are used to measure strain in steel. Typical applications include:

• Monitoring structural members of buildings and bridges during and after construction.
• Monitoring load in struts used to brace deep excavations.
• Measuring strain in tunnel linings and supports.
• Monitoring areas of concentrated stress in pipes.
• Monitoring distribution of load in pile tests.

Operation

The strain gauge operates on the principle that a tensioned wire, when plucked, vibrates at a frequency that is proportional to the strain in the wire. The gauge is constructed so that a wire is held in tension between two mounting blocks that are welded to the structural member. Loading of the structural member changes the distance between the two mounting blocks and results in a change in the tension of the wire. An electromagnet is used to pluck the wire and measure the frequency of vibration. Strain is then calculated by applying calibration factors to the frequency measurement.

Installation

Surface-mount strain gauges may be welded, bolted, or bonded to the surface of the measured member. The gauge is supplied with two mounting blocks. The mounting blocks are attached to a spacer bar and welded to the structural member. After the welds cool, the spacer bar is removed and the strain gauge is inserted in its place and adjusted to extend its range in compression or tension.

Advantages

Field-Adjustable: The strain gauge can be adjusted so that most of its range is available to measure compression or tension, as required by the application.

Permanently Attached Coils: The coils used to excite and read the vibrating wire cannot be accidentally separated from the body during installation and wiring operations.

Easy Installation: The mounting system ensures that the gauge is not damaged by the heat of welding. Also, the gauge can be repositioned or reused by removing it from its mounting blocks and inserting it in another pair of mounting blocks.

Reliable Signal Transmission: The vibrating wire strain gauge provides a strong signal which can be transmitted reliably over long distances with properly shielded cable.

For more information

Please download the PDF datasheet.