Electronic & Electrical engineering task

I would like to pay your attention, that i have to measure the liquid electrical conductivity via one wire.
If you can resolve this, please reply to me.
Please how can i manage this with Shooting a laser in, measure light degradation,or have a magnetic float and measure inductive coupling..

Thank you .

Hello Makra,

Too much is lost in translation to understand your goal. A single wire could stir water like a straw  but more info is needed about your project. Most engineers I have found at Theremin World are crippled when they have to explore outside of Computer Modeling. Your project needs bench testing and exploration.

I write because I have made some observations using the theremin concept and water. Visit my old webpage where I pass RF from a single wire through water and the signal strength varies by how conductive the water is.  Distilled water allows a weak RF signal to pass where by a few drops of vinegar or salt creates good conductivity and signal strength.  

A field strength meter or an analog AM Radio is used for signal detection.  This approach also improves the linearity of the theremin pitch field but is not very practical in physical design for the theremin.

I am not an engineer, rather a technical artist.

Christopher

Thank you for your interest.
Please put me in the right direction
I need to make a pcb card partial schematics , i don't know which component i choose

What country are you in?

The IF transformer/coil is a 42IF110-RC from Mouser, the transistor is a NPN 2N3904.

This could be wired on a small generic PCB.

I can not invent your project for you but a single RF oscillator that is modulated by a audio tone is what I would start with to monitor signal strength passing through water. Distilled water would load down the oscillator much less than conductive water.

Maybe monitor the current flow at the emitter of the transistor, place a meter between R3 and ground.

Christopher

Edit: Maybe I misunderstand what you mean by one wire and you mean one cable with two or three conductors. 

thank you  for your reply 
I ask how can this schematic measure the liquid electrical conductivity ?

"Visit my old webpage where I pass RF from a single wire through water and the signal strength varies by how conductive the water is. Distilled water allows a weak RF signal to pass where by a few drops of vinegar or salt creates good conductivity and signal strength."  - Christopher

What's happening here is simply the fact that the water forms one plate of a capacitor (with the other plate the universe).  The more conductive the water the larger the effective plate area, and so the higher the intrinsic and mutual capacitance.  Distilled water should give you pretty much the equivalent of just the wire.  Semi-conductive water would probably lower the overall Q which is generally not a good thing.

I doubt that signal strength plays a direct role.  Any variation in signal strength is probably just due to the variation in capacitive loading.

Dewster I think we could work together on this project. You use theory and I use serendipity. The original question was how to measure the conductivity of water using only one wire?

Two wires makes this simple but one wire makes it challenging, any ideas?

I am sure something got lost in translation.

Anymore my friend it is just you and me like salt and pepper or yin and yang.

Christopher

Christopher, what you have proposed is pretty good, I don't think I would have thought of it.  If the container is non-conductive and of a fixed dimension, there is probably some direct relation between intrinsic capacitance (i.e. frequency of resonance) and conductance.  Would probably work even better if the outside of the insulating container could be coated with a conductor and therefore form the other electrode, but that wouldn't be one wire doing all the work.