Grumpy_Mike:
The first is just a reed switch on a board, the second an electronic sensor.
The range of both is only a few mm.
What sort of range do you need?
You might be better off using an electronic compass.
Thank for your response,
Which one is better the reed switch or the electronic sensor?
What I have in mind is to make a small robot, setup a closed course, and let the robot find a magnetic object and beeps and continue to find the next magnetic object. I am not really sure if I need to have a large range or short range sensor to do this.
Does electronic compass better and easier to use than the reed switch or electronic sensor?