I am designing a contact electromagnetic vibration sensor. I am pretty happy with the results. It is intended for audio frequencies. Pretty light: about 4 grams and 470 ohms impedance. The output is comparable to a dynamic mic.
The sensor is a cylinder 15 mm diameter and 13 height.
It can be attached with mounting putty.
So, the problem is that I don't know how to measure the response so that I can change some parameters in the design and see what happens...
So far, this is what I got:
Function generator to sweep the audio range.
Good power amp to drive the speaker
Speaker(Flat diaphragm from Tecton) mounted on a vertical board (no enclosure)
A reference microphone.
Audio interface (Komplete 6 by NI)
Software with FFT
I am tempted to uses laser interferometry but I don't what I am doing and, unless it is easy, I would leave it out.
So.....how do I calibrate this rig so the what I get from the FFT reflects the real response? How to compensate for the non linearity of the speaker?
THANK YOU FOR ANY IDEA!
The sensor is a cylinder 15 mm diameter and 13 height.
It can be attached with mounting putty.
So, the problem is that I don't know how to measure the response so that I can change some parameters in the design and see what happens...
So far, this is what I got:
Function generator to sweep the audio range.
Good power amp to drive the speaker
Speaker(Flat diaphragm from Tecton) mounted on a vertical board (no enclosure)
A reference microphone.
Audio interface (Komplete 6 by NI)
Software with FFT
I am tempted to uses laser interferometry but I don't what I am doing and, unless it is easy, I would leave it out.
So.....how do I calibrate this rig so the what I get from the FFT reflects the real response? How to compensate for the non linearity of the speaker?
THANK YOU FOR ANY IDEA!