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Electrolytic Tilt sensor vs. Inclinometer

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HinesVA

Bioengineer
Joined
Nov 10, 2010
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1
Location
US
Hi all,

I'm a newbie to this forum and hoping to get some solutions regarding our new angle sensor. We struggled with this couple of years ago and never got to the point where we wanted.
Attached the picture is the tilt sensors that we are currently using to find the angles during cadaveric human spine motion.
We tried replacing these sensors with IC chip inclinometer (3 axis) made by Freescale Semiconductor. This was perfectly fine for measuring angles of planar motion but the problem came in when the IC chip was tilted which is always our cases.
Now my questions are..
1. Is it even possible to integrate this inclinometer to our application so that we can still measure the angles relative to gravity regardless the position of the chip?
2. Can anyone suggest any other inclinometer?

Please help! Any suggestions are going to be helpful at this point.

Thank you very much
 
You ARE measuring tilt with respect to "gravity" always. That's the basic function of an inclinometer. You just need to collect the baseline data to tell what angle you started at.


Also, please refrain from double posting.



TTFN

FAQ731-376
 
Used one of those electrolytic sensors for the first time about six or seven years ago. Fun little project, but you have to make sure you always apply an AC signal to it... if you spend any amount of time applying a DC signal, you might as well throw it away. Very reliable and accurate, but it wasn't the right sensor for the intended application.

Dan - Owner
Footwell%20Animation%20Tiny.gif
 
The DC problem can be easily mastered by using a capacitor in series with the excitation signal. Same problem with RH sensors.

There are a few parameters that needs to be identified. The ones I usually have to consider are:

A Range. How many degrees do you need to measure?
B Bandwidth. Static, Hz, kHz?
C Resolution. Degrees, arc minutes, arc seconds?
D Environment.
E Power. Battery or mains? Allowed heat generation?
F Size.
G Cost.

I am right now using inclinometers with DC excitation that consume next to no power and output a potentiometric signal. The range is +/-60 degrees and I can resolve down to one arc minute if I filter heavily. The size is 'one thumb' and the cost is depending on where you buy them. I found mine on eBay at a very low cost. My measurements are on overhead cranes and I do not need/use much bandwidth - a few Hz at most.


Gunnar Englund
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
 
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