How can I build a tilt sensor with high sensitivity and accuracy?

[hollymolly]

Hi all!

I'm working on some gravity expiraments with my professor and he's put me on the task of building a tilt sensor (to measure at any given time the tilt of the foundation with the center of the earth).

I've been looking for schematics online, but I haven't had a ton of luck unless I want to drop some serious cash. Does anyone have any ideas as to how to build one of these things?

So far he and I have been talking about a capacitor based one, but I don't know that I'll be able to create something with the sensitivity that we need.


Any ideas would be appreciated!

Thanks

 

[ranger]

You can use an electrolytic tilt sensor. These sensors work by having a capsule filled with conductive fluid. Inside the capsule, there are electrodes. The conductivity between the electrodes is proportional to how much the electrodes are immersed in the conductive fluid. There is more to it than this. You get more info from here:
http://www.sensorsmag.com/articles/0500/120/main.shtml

What you do with the output of the sensor is up to you. You may choose to digitize your signal or just do some creative things with some op-amps. Here is a circuit that does the former:
http://www.edn.com/archives/1997/042497/09di_03.htm#Figure 1

 

[berkeman]

One idea that comes to mind is to use a comination of lightly damped pendulum and an electronic micrometer. You'd need to research how electronic micrometers achieve such high accuracy and precision, and make a similar device that you attach to your pendulum. Ideally, you could make the multi-pattern part that attaches to the pendulm in an arc, and make your electronic sensors stationary.


The electronic versions are discussed at this into wikipedia.org page:

http://en.wikipedia.org/wiki/Caliper