Combined power measuring device and voltage sampling method thereof

The invention provides a combined power measuring device and a voltage sampling method thereof, and belongs to the technical field of power measurement, the device comprises an open-ended clamp meter, the open-ended clamp meter is connected to a measuring circuit board, and the measuring circuit board is connected with the ground; a conductive soft sponge is arranged in a jaw of the clamp meter, the clamp meter is provided with a current lead and a voltage lead, two signals are sent to the circuit measuring board, the current lead comes from a jaw coil of the clamp meter, and the voltage lead is connected to the conductive sponge on the inner side of the jaw; the circuit board is provided with a micro-current amplifier with variable impedance, and the micro-current amplifier is connected with the conductive sponge on the inner side of the jaw; a measured current is sent to the circuit board through the clamp meter, and a measured voltage is coupled to the conductive sponge on the inner side of the jaw through