[JT118]

It should plug in with no modification, though there are two types of FO anemometers, 

http://www.maplin.co.uk/p/maplin-replace...96fy-n82nf

And,

http://www.maplin.co.uk/p/maplin-replace...25fr-n76nf

I am not sure what the difference is or if they are different pinouts,

But I am fairly sure the one you have should plug straight in. It was the original starting point for Weatherduino some years ago.

http://www.maplin.co.uk/p/maplin-replace...96gy-n81nf

Also other info re your rain gauge question earlier.

http://www.meteocercal.info/forum/Thread...ors?page=3