Sensor needed to measure subtle linear movement

Hi,

I have an application where I'm trying to measure rather slow linear movements. For example, my device will move only about 1 inch along the X axis (no reference points) over a span of a few seconds. I've tried a 3-axis accelerometer, but the acceleration seems too slow to register any meaningful data. Is there another movement sensor that could pick this up? Would a gyro, IMU, or 6dof-type sensor be more sensitive? I don't need accurate position info, just to know when the device is slowly moving. Could a vibration sensor possibly work? Many thanks!

Andre

AndrePz:
Hi,

I have an application where I'm trying to measure rather slow linear movements. For example, my device will move only about 1 inch along the X axis (no reference points) over a span of a few seconds. I've tried a 3-axis accelerometer, but the acceleration seems too slow to register any meaningful data. Is there another movement sensor that could pick this up? Would a gyro, IMU, or 6dof-type sensor be more sensitive? I don't need accurate position info, just to know when the device is slowly moving. Could a vibration sensor possibly work? Many thanks!

Andre

I think it would have to be something mechanically coupled to the device but referencing a stationary surface. Say like an encoder with a wheel attached that rotates as the devices moves. Or a LVDT sensor.

http://www.google.com/search?q=lvdt&hl=en&tbo=d&source=lnms&tbm=isch&sa=X&ei=bDUXUcXbNNHbqwGFvoCoBw&sqi=2&ved=0CAcQ_AUoAA&biw=1058&bih=792

Lefty

Unfortunately for my application, it is impossible to have a stationary reference. I'm measuring muscle movement. I just need to know when the device is being moved, albeit by a small amount. Does anyone know if this vibration sensor could work to detect subtle movement? http://www.rapidonline.com/Electronic-Components/Non-mercury-vibration-sensors-72379/?sid=b2427a8f-b17b-4545-ae5b-c1abe0c864e0

Thanks.