How to detect a magnetic field

Hello,

I want to know how I can detect a magnetic field.
I know there are some devices like tesla meter or electronic compass module etc...

But I would to learn how I can detect the field with a coil and its appropriate electronic... A more physical solution..

Thanks!

The solution is different for DC (static) and AC fields. Only the latter can be detected with a coil (or the coil has to be moved). Hall sensors and flux gate magnetometers are usual solutions to measure static fields.

I want to detect a static field (magnetic objects)...

So, with hall sensors or flux gate magnetometer, will a low magnetic field be detected ?

I want to detect the magneticity of a screw for exemple..

Thanks

u can detect a magnetic field by using a coil and ammeter. connect the meter in series with the ammeter then move the coil and note if the indicator have been moved, then this means that there is a magnetic field