Deflection measuring device of test piece in fireproof ultimate test

The utility model discloses a deflection measuring device of a test piece in a fireproof ultimate test. The deflection measuring device comprises a press head, a probe rod, a double-acting cylinder, a compression air passage control device, a stay cord displacement sensor, an analog-to-digital converter and a computer. The press head clings to the surface of the test piece. One end of the probe rod is fixedly connected with the press head. The compression air passage control device is connected with the double-acting cylinder. One end of a piston rod in the double-acting cylinder is connected with the probe rod and the other end is connected with a traction rope end of the stay cord displacement sensor. The stay cord displacement sensor is connected with the computer via the analog-to-digital converter. The deflection measuring device is advantaged by high temperature, smoke and corrosion resisting ability, easy installation and precise measurement.