Salt Water Chlorination Cell

I have purchased a fairly reasonably priced older chlorinator cell and
would like to install it on my swimming pool. I plan on using a 12v DC
power supply. I had a suprise when I recieved the cell. It has three
probes instead of just two. I used my multi-meter to discover the
continuity of the probes to the plates inside the cell and it is like
this:

| | | | | | | | |<<<<<<<<<plates
0 0 0<<<<<<<<<probes
(there are actually more plates between the ones on the outside and
the middle)
I was wondering what the three different probes were for? I am
guessing that it is set up for reverse polarity to cycles to reduce
build up on the plates. however, I'm not sure what should be negative
and what should be positive.

TIA

Jojo

 

I have the same cell configuration, and looking
at the pool psu, the third terminal acts as a
gate driver for the MOSFET drivers.

Hope this helps.