VW Embedment Strain Gauge
VW Embedment Strain Gauges are used to measure strain in reinforced concrete and mass concrete.
Operation
The body of the strain gauge is a steel tube with flanges at either end. Inside the body, a steel wire held in tension between the two flanges. Strain in the concrete causes the flanges to move relative to one another, increasing or decreasing the tension in the wire.
The tension in the wire is measured by plucking the wire with
electromagnetic coils and measuring the frequency of the resulting vibration. Strain in the wire is calculated by squaring the frequency reading and multiplying a gauge factor and a batch calibration factor.
Test each sensor before installing it. Use a readout and an ohm meter to conduct these tests.
• The VW sensor reading should be about 895 Hz.
• The RTD reading should be close to the ambient temperature.
• Resistance between the orange/white and orange leads should be about 300 ohms.
• Resistance between blue/white and blue leads should be about 2k ohms.
Get pdf VW Embedment Strain Gauge
