I need a sensor for a small, handheld, plastic trash detector similar to a small metal detector. The object is to find plastic trash buried under leaves etc. following a storm, hurricane or flood. The best I can tell is I need a very low ultrasonic detection frequency of about 25 kHz, or lower If it’s out there, to penetrate leaves mainly or other organic material but bounce off hidden plastic. I just want simple detection which would fire a buzzer or light to tell someone where to look. What do you think would work? Thanks in advance
That sounds like a difficult, if not impossible goal, especially combined with “small” and “simple”. “Plastic” covers an astonishingly wide range of materials.
The best I can tell is I need a very low ultrasonic detection frequency of about 25 kHz
Where did this idea come from? Please post a link, or explain the physical principles.
Only things I can think of that might work are ground penetrating radar or a trained dog.
The idea came from a walk in the woods after a storm and I kicked up some plastic covered with leaves. The 25kHz or lower frequency comes from reading somewhere that low frequencies were better at penetrating soft targets like leaves. I’m an old metallurgist and this is way out of my expertise.
I think you’re on the same track with me. Radar would work but the ‘small, handheld and inexpensive’ part is pretty elusive. I’m envisioning something your average Joe could buy or make for under $500.
Check out some other GPR projects online…they’re usually on wheels because the sensor needs to be close to the ground - I’ve seen some on youtube, hackaday and tom’s hardware IIRC
How would an old metallurgist explain the difficulty of using hands- and visionfree sensors for finding the dime hidden in a can of pennies? Or the aluminum among the brass shavings?
Good question, Ha!