Abstract: A metal detector for buried and abandoned chemical weapons is provided, comprising: a transmitting circuit to transmit a detection signal; a frequency selection unit electrically connected to the transmitting circuit and configured to regulate a frequency of the detection signal; a receiving circuit to receive a reflected signal returned from the substance detected; an analog-digital conversion unit electrically connected to the receiving circuit and configured to convert the reflected signal into a digital signal; and a control unit electrically connected to the analog-digital conversion unit. In the present disclosure, the frequency of the detection signal can be regulated by changing a current frequency of the transmitting circuit, so that several forms of iron compound can be detected, thereby increasing the detection accuracy of the ACWs.

Abstract: A metal detector for buried and corroded pipeline is provided, comprising: a transmitting coil configured to transmit a detection signal to a pipeline; a frequency selection unit electrically connected to the transmitting coil for regulating a frequency of the detection signal; two receiving coils respectively and symmetrically disposed at two opposite sides of the transmitting coil for respectively receiving a reflected signal returned from the pipeline; an analog-digital conversion unit respectively and electrically connected to the two receiving coils for converting the reflected signal into a digital signal; and a control unit electrically connected to the analog-digital conversion unit. In the present disclosure, by comparing intensities of the reflected signals received by the two receiving coils, it can be efficiently and accurately determined whether corrosion has occurred to the pipeline.