Magnetic pick-up sensor series A2S...

Detecting speed of rotating steel profiles, specifically at high speed, and under high temperature (turbines, turbo-blowers, for instance). Also, the alternating magnetic field around transformers, ignition coils, or rotating magnetic parts. Output signal varies with frequency and gap, therefore requiring high sensitivity of the receiver input, or a local pre-amplifier.
Not for low speed applications.These sensors do not require supply. Various design models available. 
A specific system is available with sensor up to 200 °C and signal preamp V185S for long transmission.

Click here for data sheet