How is streaming potential measured?

[This paper](http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1548283&tag=1) describes the measurement of streaming potential using a potential divider configuration. However it is unclear where the potential difference is created. From the diagram it appears that it is created across the length of the flow channel, so at one side there is a low potential and the other a high potential. However this doesn't seem to agree with the description of streaming potential. From other sources it appears that the potential difference is across the outside of the flow channel near the surfaces, to the inner middle of the flow channel (at the point furthest away from the surface). Which is correct?


EDIT: there isn't a tag for electro-chemistry, so I have just put this under battery chemistry. However this is not necessarily for a battery.


