| 摘要 |
According to the present invention, a duct thinning detecting device using a double core is devised so as to evaluate corrosion or changes in thickness (thinning) caused by corrosion of a duct which is covered by an insulator, which is to say losses in the duct, from outside the insulator by using eddy currents by means of a differential probe having a double core without dismantling the insulator in non-destructive testing. More specifically, the present invention comprises: a probe unit having a double core, a drive coil and a differential Hall sensor; a pulse-generating unit which is connected to the probe unit and generates a wide-band pulse voltage that is applied to the drive coil; an amplification unit which is connected to the probe unit and amplifies a measurement signal induced in the Hall sensor; an A/D conversion unit which is connected to the amplification unit and converts the measurement signal to a digital signal; and a control unit which is adapted to control the probe unit, the pulse-generating unit, the amplification unit and the A/D conversion unit while at the same time storing and displaying the digital signal. |
