Vibration measuring, DIY?!

positron

Any ideas on how to DIY a vibration measuring device?

Professor_Fink

positron wrote:

Any ideas on how to DIY a vibration measuring device?

How sensitive does it have to be? You could just use a pendulum with a heavy weight. Use a long solid rod to attach the mass to the pivot. Attach a pen somewhere along the rod so that it sweeps out an arc on some paper when the pendulum swings. Vibrations will cause the base and pivot to move, but the mass will remain largely stationary, and so you can record the amplitude of oscillations. For more sensitive measurements, you may need to extend the rod (without moving the mass) so that the movement of the pen is exaggerated.

positron

Thanks Professor Fink!

It has to be very sensitive, I am afraid... At work, the floor is vibrating like mad - one can't feel it straight away walking in, but when someone spends 8 - 10 hours like I do at my desk, it really gets to me - it kinda starts, goes on for about 10 - 15 mins and stops, and it repeats through out the day, or irregular intervals. I think its some motor / machine on the basement or ground floor.

I thought about a pendulum, but couldn't figure out how to make it sensitive. A long handle to the pen is the key, and somehow should get a little motor to pull the paper at a constant speed through the "write window".

Professor_Fink

positron wrote:

I thought about a pendulum, but couldn't figure out how to make it sensitive. A long handle to the pen is the key, and somehow should get a little motor to pull the paper at a constant speed through the "write window".

Hi,

Extending the distance of the pen below the mass would allow you to increase accuracy essentially arbitrarily. If you are only interested in measuring the vibration, and not when it occurs, then there would be no need for the motor.