CAVE detector diy

[Alexismex]

A small cave detector for to easy make yourself.

[zenit52]

Hi Alexismex,
please explain more to us this cave detector ...!!!

you use microphone and one amplifier to listen echo sounds ?
with best regards... zenit52

[epitopios]

CAVE detector diy

you mean something like this:http://www.senscomp.com/

[Alexismex]

Hello Epitopios , no it is not the same ,this one in the page link is a ultrasonic detector to use in air...
Hello Zenit52, yes you use a mini cassette recorder integrated amplifier to amplifies the sound of the piezo...you must fix the piezo well in the pvc tube with epoxy and place a smouth rubber(like bicycle rubber) to protect the piezo ....
The piezo must have contact with soil ...you maintain it with pvctube...
The echo came when you percut with a mass at the vertical of the hole ....
You must have a minimum volume to resonate let say 1X1X1 to resonate ...
This simple and cheap configuration work great for the price.... for discover chamber or tunnel to 2-5 meters depending of the volume of the cave and the weight of the mass....
Alexis.

[montepollock]

Is similiar in principle to the device used to locate oil,but the force was from explosive charge

[Geo]

Hello Epitopios , no it is not the same ,this one in the page link is a ultrasonic detector to use in air...
Hello Zenit52, yes you use a mini cassette recorder integrated amplifier to amplifies the sound of the piezo...you must fix the piezo well in the pvc tube with epoxy and place a smouth rubber(like bicycle rubber) to protect the piezo ....
The piezo must have contact with soil ...you maintain it with pvctube...
The echo came when you percut with a mass at the vertical of the hole ....
You must have a minimum volume to resonate let say 1X1X1 to resonate ...
This simple and cheap configuration work great for the price.... for discover chamber or tunnel to 2-5 meters depending of the volume of the cave and the weight of the mass....
Alexis.

Hi Alexismex.
Did you try it???
Regards

[Alexismex]

Hello Geo , yes i make it , it work but for more sensibility you must use a geophone o make it with a magnet and a coil (1000 turn minimum), also in this link you can buy it , i have buy geophone and it is the best and their are cheap because of used , also i have the amplifier
http://psn.quake.net/geophone/index.html
http://psn.quake.net/eqamp.html
the technique is simple you make a percussion with a big mass and you "listen the echo " with your geophone
Alexis

[Geo]

Hi Alexismex.
Thank you.
For to find a cave at 1.5m depth from 2..3m distance, what big mass i need so to hear the echo???
Also do you have schematic from preamplifier, or i must calculate one??

Regards

[wam]

Nail gun or impact electric driver.

Nail gun or impact electric driver.
Did one experiment with above as wave impact generators?
Would be nail gun suitable and what distance for locate
caves or underground bankers?
Could one brief why sensor must be low frequency?
I thought that shock wave in the ground travels faster then 10Hz
so there is need for wider range of response.
Did one try to make geophones out of old large speakers?
I better ask before try.

[Alexismex]

Hello Wam,
Why make a geophone from old bass speaker ( i try it and loose time!!!) ?? if the used geophone exist ...it is compact and work too much well and with a very big sensitivity ...see the post before for the geophone....
Alexis

[Toni]

Maybe Yukon DSAS - Directional Sound Amplification System?

http://www.sailgb.com/p/Yukon_DSAS_D...cation_System/

[fitz]

Better than dropping a heavy weight???

So what if I rig up some sort of nail gun to make a big thump? If the gun uses a blank .22 cartridge it can really make a large THUMP and it would be easy to use. Not certain if you can get these nail guns outside the US but I might buy one and try it.
I found a link to a test.
http://www.aeic.alaska.edu/input/west/22source/



Just an idea.
Fitz.

[Valchev]

Is there somebody who know examples similar to http://www.aeic.alaska.edu/input/west/22source/ but that show how with seismic sistem can to detect small objects from 1m to 2m diameter in depth 2m , 3m or more in loam?








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