Resonance meter

[TinselKoala]

Thanks, I think.
How would I approach a fluid?
Depends on the fluid...Scots whiskey, I approach with glee...

Seriously, it would depend on the purpose and which resonance I wanted to excite.
Many so-called fluid resonances are actually acoustic resonances of the chamber containing the fluid...

Are we trying to dissociate water into hydrogen and oxygen using resonant oscillations from a TC? I don't know if that can be done, really. The bond resonance frequencies may be too high. But certainly the secondary discharge can dissociate water.

But to first order, if you are looking for acoustical or other mechanical resonances, you can do the same thing as with the rock, with a couple of appropriate piezo sensors. You can even do it with only one piezo, if you monitor the power to it, because when you hit a resonance you will generally see the driving piezo power dip.
For higher-frequency electrical resonances the same ideas apply, you just use different transducers, depending on your theory. You could stick plates in the water, pretend it's a capacitor, put it in an LC circuit and sweep the inductance. If you hit a resonance you'll see it in the power trace. You could wrap a sensing coil around the tank, feed RF into the tank with another coil.

[ramset]

TinselKoala
Im not aloud to use whiskey in my experiments anymore [very sad    ]
However THANK YOU for sharing your ideas on this
I appreciate your contributions to this forum IMMENSELY {as I am quite sure others do also]
  Chet