Diff speed sensor info

[Pond]

Really struggling to find the answer to my question on t'internet, so here goes.....

I need to find out the number of 'trigger points' for the speed sensor inside the diff on my car.
I think it is a Torsen diff (3 litre Z3)
I think the diff ratio (final drive ratio?) is 3.07

But I need to know the number of pick up points that the sensor translates into pulses. I am leaning toward just one, but can't find the answer.

Anybody?

 

[Rudyrov]

Google Image Result for https://i.ebayimg.com/images/g/vOUAAOSwN81WD2Np/s-l400.jpg

looks like 9 pins

 

[Pond]

Google Image Result for https://i.ebayimg.com/images/g/vOUAAOSwN81WD2Np/s-l400.jpg

looks like 9 pins

Thanks but that confuses things even more!
I don't have an LSD and don't think (but could be wrong) the M54 diff is 'open'.

 

[Delk]

I think they are all the same number of blades or whatever you want to call them.

There are several diameters to fit different diffs and covers but the numbers are the same per rotation