Originally I was going to use accelerometers, but they are to big for the disk I'm trying to measure.
Basically I have a set of planetary gears for which I need to measure the vibrations in the x and y components, mainly. I´ll be performing modal testing with an instrumented hammer and a laser single point vibrometer.
Since my gears are straight teeth spur gears I didn't take into account the "z" coordinate or vibrations of the system for my dynamic model, so if I point the laser perpendicularly to the gear´s plane the vibrations being measured by the laser will be those in z, which I'm not interested in.
I read that if I had two Laser Doppler Vibrometers I could measure the in-plane motions I'm looking for, but since I only have one I was wondering if there´s a way of decomposing the projected component by pointing the laser at certain angle?