Position Sensing Project Using Hall Effect Sensors

Hi Everyone,

I wanna tackle a project with position sensing; I'm thinking of using hall effect sensors but i'm not sure what would be best (specifically what hardware I should use).

I want to be able to see what amount of weight my air mattress can support. I'm thinking of putting sensors on the bottom of the bed and on the support surface. Then i'm going to add weight until the bed touches the ground.

Specifically, i want to be able to see how much weight results in a vertical displacement, until the weight (or a person's body) touches the floor.

Do you think hall effect sensors would be my best bet? Any specific hardware recommendations?

air pressure sensors?

Richard: I was afraid the distance would be a problem; the bed is approximately 8inches tall. I don't need to measure weight directly; i'm interested in knowing what weights correspond to deflection (I know you can use Pascal's Law and Boyle's Law to find this, but this would be too hard to calculate by hand).

Groove: I think air pressure sensors might be helpful, but again, i'm more interested in the deflection of the bed.

The bed is basically 20 transverse cylindrical air cells. I wanted to attach sensors to each one to measure deflection corresponding to weight i'm adding to the bed. I'm going to have to be clever about this if the Hall Effect sensors isn't feasible.

Use two coupled coils, like a transformer. Drive one with an oscillator and measure the pick up signal with the other. Use a frequency like the RFIDs at 125KHz. You should be good for 8 inches.