The present disclosure provides a foldable portable metal detector including: a detection coil disk; a waterproof circuit protection compartment; a circuit component; a folding and fixing component; a fastening component; and an extension rod; the circuit component is inserted into the waterproof circuit protection compartment; the extension rod is fixedly connected to the waterproof circuit protection compartment; the circuit component is electrically coupled to the detection coil disk; the detection coil disk is provided with a bracket provided with a first through-hole and a second through-hole; the fastening component is provided with a bolt and a fixing column; the waterproof circuit protection compartment is provided with a connector provided with a connection hole; the bolt penetrates the connection hole and the first through-hole in sequence, the fixing column penetrates the second through-hole; and the waterproof circuit protection compartment is selectively rotated around the bolt.

The present disclosure provides a foldable portable metal detector including: a detection coil disk; a waterproof circuit protection compartment; a circuit component; a folding and fixing component; a fastening component; and an extension rod; the circuit component is inserted into the waterproof circuit protection compartment; the extension rod is fixedly connected to the waterproof circuit protection compartment; the circuit component is electrically coupled to the detection coil disk; the detection coil disk is provided with a bracket provided with a first through-hole and a second through-hole; the fastening component is provided with a bolt and a fixing column; the waterproof circuit protection compartment is provided with a connector provided with a connection hole; the bolt penetrates the connection hole and the first through-hole in sequence, the fixing column penetrates the second through-hole; and the waterproof circuit protection compartment is selectively rotated around the bolt.

A hypergravity model test device for simulating a progressive failure of a shield tunnel face, including a model box, a shield tunnel model, a servo loading control system and a data acquisition system. The servo loading control system includes a servo motor, a planetary roller screw electric cylinder and a loading rod. The data acquisition system includes a displacement transducer, an axial force meter, a pore pressure transducer, an earth pressure transducer and an industrial camera. The servo loading control system is connected to an excavation plate through the loading rod to control the excavation plate to move back and forth along an axial direction of the shield tunnel model at a set speed to simulate failure of the shield tunnel face. A method for simulating a progressive failure of a shield tunnel face is also provided.

A hypergravity model test device for simulating a progressive failure of a shield tunnel face, including a model box, a shield tunnel model, a servo loading control system and a data acquisition system. The servo loading control system includes a servo motor, a planetary roller screw electric cylinder and a loading rod. The data acquisition system includes a displacement transducer, an axial force meter, a pore pressure transducer, an earth pressure transducer and an industrial camera. The servo loading control system is connected to an excavation plate through the loading rod to control the excavation plate to move back and forth along an axial direction of the shield tunnel model at a set speed to simulate failure of the shield tunnel face. A method for simulating a progressive failure of a shield tunnel face is also provided.

A system for passive microwave remote sensing using at least one microwave radiometer includes a fixed body portion and a mobile body portion. The mobile body portion is configured for rotatably coupling with the fixed body portion for rotation about a rotation axis. The mobile body portion is configured for supporting the microwave radiometer therein such that the microwave radiometer rotates about the rotation axis when the mobile body portion is rotated about the rotation axis such that a polarization axis of the radiometer is aligned with an earth axis. The fixed body portion includes a motor mechanism for effecting rotation of the mobile body portion. In an embodiment, the mobile body portion includes a plurality of body section, each body section being configured for supporting a microwave radiometer therein. In another embodiment, each one of the plurality of body sections is configured to be interchangeably coupled with each other.

A system for passive microwave remote sensing using at least one microwave radiometer includes a fixed body portion and a mobile body portion. The mobile body portion is configured for rotatably coupling with the fixed body portion for rotation about a rotation axis. The mobile body portion is configured for supporting the microwave radiometer therein such that the microwave radiometer rotates about the rotation axis when the mobile body portion is rotated about the rotation axis such that a polarization axis of the radiometer is aligned with an earth axis. The fixed body portion includes a motor mechanism for effecting rotation of the mobile body portion. In an embodiment, the mobile body portion includes a plurality of body section, each body section being configured for supporting a microwave radiometer therein. In another embodiment, each one of the plurality of body sections is configured to be interchangeably coupled with each other.

An amphibious portable magnetism detector includes a first housing, a first wiring tube, a first magnetic field sensor, and a central control device. The first housing defines a first inner space and a first through hole in communication with the first inner space. The first wiring tube is connected to the first housing with a first leak-tight seal formed between them, and in communication with the first inner space via the first through hole. The first magnetic field sensor is disposed in the first inner space and configured to detect a magnetic field at a target area and generate a first detection signal. The central control device is electrically connected to the first magnetic field sensor and configured to receive the first detection signal and output a first magnetic field value according to the first detection signal.

An amphibious portable magnetism detector includes a first housing, a first wiring tube, a first magnetic field sensor, and a central control device. The first housing defines a first inner space and a first through hole in communication with the first inner space. The first wiring tube is connected to the first housing with a first leak-tight seal formed between them, and in communication with the first inner space via the first through hole. The first magnetic field sensor is disposed in the first inner space and configured to detect a magnetic field at a target area and generate a first detection signal. The central control device is electrically connected to the first magnetic field sensor and configured to receive the first detection signal and output a first magnetic field value according to the first detection signal.

A metal detector 20 includes a detection signal acquisition unit 31, a threshold value setting and updating unit 32, and a determination unit 33. The detection signal acquisition unit 31 acquires a detection signal that changes according to the detection strength for a rebar W1 contained in concrete W, on the surface of the concrete W. The threshold value setting and updating unit 32 sets a threshold value in order to determine the presence or absence of the rebar W1 on the basis of the maximum value and/or the minimum value included in the acquisition results for the detection signal acquired by the detection signal acquisition unit 31. The determination unit 33 determines the presence or absence of the rebar W1 by using the threshold value set in the threshold value setting and updating unit 32.

A metal detector 20 includes a cover 25, a detection signal acquisition unit 31, a determination unit 32, a display unit 24, and a display control unit 34. The cover 25 is removably attached to a tip portion 18 of a handheld power tool 10. The detection signal acquisition unit 31 acquires a detection signal that changes according to the detection strength of rebar W1 in concrete W. The determination unit 32 determines the presence or absence of the rebar W1 on the basis of the acquisition result acquired by the detection signal acquisition unit 31. The display unit 24 displays the presence or absence of the rebar W1 by lighting lamps in different colors. The display control unit 34 controls so as to switch the color of the light displayed on the display unit 24 on the basis of the determination result by the determination unit 32.