I want to separate plastic bottles and glass bottles. Which sensor is best for my project. And it must be suitable with arduino. Until now I haven't found the answer yet :( . This is my college project
throw them in water, the plastic bottles will float ...
How would you yourself separate them?
Post a list of the different properties you considered yet?
e.g. the plastic bottles will float and the glass bottles will sink (example above)
How about a microphone and a solenoid? Trigger the solenoid to "thump" the bottle in question - a glass bottle should have a marked difference in sound frequency than a plastic bottle.
You might try a light sensor - perhaps the reflection off a glass bottle is different to a plastic bottle? Or shine a laser or other light thru the bottle, and measure that?
How about a capacitive sensor? Two metal plates between which the bottles pass - perhaps a glass bottle has a different capacitance than a plastic bottle?
If the plastic bottle are PET - you might look at this thread:
Measure a weight.
Descartes is your friend.
Every material have his own indice of diffraction.