Measuring device placement.

<p>Measuring device placement.</p

Picture of wireless node.

<p>Picture of wireless node.</p

Block diagram of wireless data acquisition node.

<p>Block diagram of wireless data acquisition node.</p

RSSI value of different places.

<p>RSSI value of different places.</p

Diagram of equivalent circuit model.

<p>Diagram of equivalent circuit model.</p

AD Command Response of Xbee Pro.

<p>AD Command Response of Xbee Pro.</p

Topology of three kinds of network.

<p>Topology of three kinds of network.</p

Framework of the space charge measurement.

<p>Framework of the space charge measurement.</p

Distribution of space charge around HVDC transmission line.

<p>Distribution of space charge around HVDC transmission line.</p

Experiment results of space charge density under different voltage levels.

<p>Experiment results of space charge density under different voltage levels.</p