Hi,
I am a 2nd year Healthcare Engineer. I need advice on which sensor to use.
My sensor needs to measure the rotation(speed) of an axis.
I'd love to hear from someone soon,
The most obvious way (to me at least) would be to use a rotary encoder
Hi,
What speed?
Thanks.. Tom.. 
I have to ask: If you're looking for help why be so abbreviated and vague about what you need? As a (future) engineer you should know the importance of clear requirements specifications.
Listing as many details as you can about what you need will garner more positive responses than leaving it all up to guess-work by those from whom you seek help.
What sort of "axis"? What is its size and material? What is the speed of the "axis"?
It's easy to get bored with these useless guessing games isn't it?
Steve
I hope the OP is not waiting for one of the forums ultra-reliable notification emails. :o :o :o :o :o