Does anyone know what the difference is between a 'hall-effect sensor' and a 'inductive sensor'?

Hall effect sensors work by sensing the presence of a magnetic field. These sensors can be position calibrated.

Inductive sensors work on a piece of metal passing the head(as in ABS toothed wheel) Steel is better than ali here. Inductive sensors can be passive, ie require no power.

Does that help?

Ben (Luego)

yeh it does thanks
tommy

Inductive are passive devices, they are usually two wire andgive out a fairly small signal. The air gap between the sensor and the trigger wheel has to be extremely small otherwise you get no signal.

Hall effect sensors are active devices, the leads usually have three wires. They need a power supply as mentioned. They give a larger signal and are slightly less penickity about the air gap (though it still has to be pretty small).

^^^ wot they say.

hall effects detects presence of a magnetic field and it polairyt (i.e. direction)

inductive measure distortion in a magnetic field - they usually have a magnet built in and when a metallic object is brought near, it will affect the magnetic field and the change is measure in a wire coil. Note change highlighted - the object needs to be moving past the sensor for a signal to be generated; not the case for hall effect.

Old thread resurrection alert!

I'm trying to work out how to mount my speedo sensor. This one came with the car http://uk.farnell.com/schneider-electric-telemecanique/xs608b1pal2/proximity-switch-m8-pnp-no-cable/dp/4254697 but was not fitted. According to the weblink it is an inductive sensor, and according to the below thread they are usually 2 wire and fussy about setup. Mine is 3 wire, power, earth and signal.

Does anyone have any experience of these sensors? Are they any good? I'm guessing due to the specified measurement distance and thread below that the bracket has to be stiffer than a stiff thing. The bracket I've just made is alloy and a bit floppy, I think I'm going to add some webs to stiffen it until it's MOT'd and I can get it to my house and weld a steel one on (see my other thread).

Speedo is a Smiths/CAI Telemetrix, and I'm mounting off the front of my english axle sensing prop bolts.

While we are on the subject can anyone tell me the gap distance on an inductive sensor
Thanks

the ones i used to use for my job, you used to screw them in till they touched a peak then out a full turn... 1mm pitch thread so 1mm gap