The characterization of giant magnetoresistance sensor for prototype of bridge deflection measurement

The Shift is the displacement of the object’s position from its initial state to its final state. Shifting phenomena can be found in landslides, cracks in building construction, or bridges. One of the sensors used to detect deflection is the GMR sensor. The GMR sensor is a sensor that can detect changes in magnetic fields. The configuration of permanent magnets and GMR sensors can be used to detect micro-order shifts. This research was conducted in several stages, namely making a bridge model, making a sensor circuit, signal conditioning circuit and testing characteristics. The research method is to place a permanent magnet on the static and GMR sensors on the part that is easily shifted on the bridge. The test results show that the GMR sensor can detect shifts in the 10micro order and the sensitivity of the GMR sensor can be obtained at 0.0131 Volt / mm. The voltage response of the GMR sensor to shift distance is exponential. The maximum shift test is obtained at half the bridge span. This research can be used for monitoring bridge shifts.