What is that thin pipe on race car's bonnets or roofs?

[eg01st]

I am curious, but could not find answer. See the picture to get what I mean. It's facing the front so it must be taking in air. Does it measure air temperature?

 

[Jacco van der Zaag]

It's a pitot tube. Used to measure flow.

 

[eg01st]

It's a pitot tube. Used to measure flow.

Thanks, now I can do more detailed googling by that name.