I'm looking a thickness measuring system.. I heard some kinda laser systems can do, but i can not find that. How can i measure plastic surface 0-10 mm and 0.01 tolerance (without touching) ?
I think ultrasound echos could be used,if this measurement could be done under water. Since the propagation speed are certainly different just measuring timing from different echos it could be possible....
Just another idea.......
Maybe doing the same think that digital photo cameras do to focus you could acheve good distance measurement......
High luminecense LEDs could also help. The light emited could be modulated. Than you could measure the phase change of the echo to find the distance.
Interference mavbe a good idea....
The measurement could be improved by averaging......
But 100um precision can be difficult to get....or maybe even impossible....
use laser whose direction form 45 degree to the table and ccd camera on other side to receive reflected from table laser light . When material to be measured will be put to table, place on ccd radiated with laser will be changed Difference between pixels (without material and with amterial) on ccd will be proportonal to thickness . You can increase resolution if put lenzes in front of ccd .
for 1 k x 1 k pix ccd sensor and 10 mm sensor length you have 10 um spaced pix onccd camera .