And how to connect to the Spirit Pro?

Regards
Tom

like this?

_________________
Spirit System (Spirit W1, RS & GTR & all the others)
Spirit Wave & JETI DS 12
http://www.habada.cz

Ok, not like this:

http://manual.spirit-system.com/index.p ... RPM_Sensor

but, does it work well?
Because this sensor is not listed

For the Pro you can link it like it is shown in your link or like the other link (if i am not mistaken) . If you have your AUX2 free then i would this method, because its the cleanest installation.
You would even be able to make a Y-cable and link + and - with a servo lead to power your sensor. Or use Ch0 for power supply.
The link from Habásek is showing the only way of wiring with a normal non pro spirit without the use of a y-cable (asuming you dont have a spekturm sat there)
So either way will work with rpm signal on PIT and GND and Plus from somewhere of the unit.

If the sensor itself will work, i can not tell you.

is also a matter of voltage
on aux or ch0 you pick the same voltage of all electronics
on sat port you pick the regulated 3.3v

it all depends on voltage requirements of the sensor