Construction systems and methods for anchoring a structural member of a building to a base member of a building including one or more anchoring devices, each anchoring device having a first portion and a second portion. The trigger circuit outputs a trigger signal in response to a voltage difference between the power source lines, such as occurs when an electrostatic discharge is received along the power source lines. When receiving a signal in a strong electric field area having a high possibility that a strong interference signal exists, a gain of the amplifying circuit is set to be smaller than that in a case of receiving a signal in a weak electric field area by a gain switch signal output from the gain switch controller. This main basin is generally filled with water.