Ultra sensitive hall effect sensor/switch

[commerou]

Hi there
I have just started a new project, and i need to trigger on some magnets. At the moment I am using a reed relay, but i really want to use a hall effect switch because the reed relay triggers randomly because of vibrations.
The hall effect sensor needs to trip at around 0.5 mT (5 Gauss)
Does anyone know of any hall effect sensors around that, I cant seem to find any?

Best regards
Commerou

[dumle29]

Bump, I need to know this as well :S

I have been looking at GMR sensors, but even these seem to not be sensitive enough.

[mjkuwp]

how about this

http://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Missiles-Munitions/HMC_1001-1002-1021-1022_Data_Sheet.pdf

Digikey 342-1001-5-ND

It looks to require extra circuitry to get the function you desire but sensitivity is there.

[Alexei.Polkhanov]

If you really need to measure small and very small magnetic field you better go with flux gate magnetometer sensors like this for example: http://www.speakesensors.com/products.htm. Hall effect sensors just not made that sensitive.  these are around $50.

I have feeling that for your application you should use some kind optical sensor (reflective or interrupt) instead of magnet+reed relay.

Also you may notice that in many current sensors hall effect sensor is placed into a gap in magnetic core around which wire is wound to compensate for low sensitivity of hall effect sensors.