Inductive Proximty Switches Sensing Aluminum?

[motoboy]

I was working with some Osiprox Proximity sensors from Telemecanique and surprised to find out that they can detect aluminum (although at only about half the distance of steel). This flys in the face of my understanding of how an indutive sensor works. That being you basically have a transformer with no core and the sensed object becomes the core and induces a detectable voltage in the seconday windings. Since only magnetic materials can conduct flux (and be an effective core) how can an indutive sensor sense aluminum???

Please point me in the right direction if my logic is off.

 

[wagnerc]

LOL. "Would the metal detector trip if u had a large long closed tube of salt water?" Like a large long closed tube like ur colorn that is retaining water??

 

[itsmoked]

I shant think you should have that much:

a)water sitting in your colon (or you wouldn't be sitting but running)

and

b)that much dissolved salt in solution.