Vibration Table Sensor?

Hello Guest,

I found this for you:

Fiber-optic vibration sensor

The sensor comprises a vibrating sheet (1), mechanically connected to the body (5A) to be analyzed, and an optical triangulation recording system for recording the displacements of the movable part of the sheet, in particular the free end (1B) opposite to that which is restrained. The recording system comprises two optical fibers (7, 9) ending in microlenses (10, 12) having optical axes mutually inclined and converging in the movable part (1B) of the sheet.

http://www.freepatentsonline.com/5063781.html

Hope that assists you....

The standard way to measure and monitor vibrations such as this is to use an accelerometer attached to the table, with the correct conditioning amplifier you can take measurements of velocity acceleration and amplitude etc...

Much simpler than messing about with optics and multiple sensors. Simply attach the accelerometer and measure!

John.

Guest:

If you only want to know displacement, attach a $5 laser pointer to the shaker table and point it at a ruler mounted on the wall. Velocity and acceleration can be derived from the displacement (and frequency).

Good luck.

DickL

Do a search on proximity probes, probably your best bet.

I agree with the accelerometer solution as the best suited.

Anyway here is my small contribution: You can attach a spring loaded rope potentiometer to the table and mount the other end to a fixed point. This will give you a voltage proportional to the displacement. If you only want to measure the displacement, a normal multimeter with peak retention function is enough. If you want more information and have a data adquisition system, then you can get not only the displacement but also the other relative parameters: velocity, acceleration and frequency.

I've made it to measure piping systems transients. Furthermore, to avoid the possible variations in the primary voltage, I measure it and the software (Labview or DasyLab from NI) divided the signal by the feeding voltage.