On Aug 26, 2007, at 6:31 PM, R.C.Macaulay wrote:
Horace wrote,
The idea is to apply a very sharp square wave to a long thin tube of
liquid material and measure the waveform that comes out the other
end. It is then just a matter of building a database using samples
of known materials. It might be useful as a cheap preliminary
screening method for some kinds of water pollution.
Howdy Horace,
Interesting idea you have for a "receptive spectrometer".
Suggest some parameters and I will get one on our instrument guys
to build one. We would use the guts of something we have laying
around and see where it leads . We have some 5/8" od x .035 grade
2 titanium tubing that could work,
The tubing has to be an insulator. I used tygon tubing and loaded it
with a peristaltic pump. The experiment is described at:
http://www.mtaonline.net/~hheffner/Ecell10m.pdf
Note that the possible ion mass spectrum showed up in a *current
probe* I made by winding some turns of the 1/8" Tygon tubing around
a small core, and using a few turns of wire as a secondary. This was
noted on page 11. This might be called a fluid to copper
transformer. A standard current probe clamped round the Tygon might
work just as well. I used a Pt anode and NiCr cathode, but a mass
spec. might better use a copper to fluid pulse driver and a fluid to
copper current detector. I think at some point I switched to all Pt
electrodes for investigating current waveforms. A scope with a very
fast single-shot trace is essential for obtaining the spectrum.
You are correct about water pollution applications. The industry
will transition to radical new water treating technologies within 5
years and we don't have the instruments for the technology..One of
the tasks involve transmutaton of certain nitrogen compounds that
otherwise present troublesome obstacles to destruction.
The copper to fluid transformer may be a useful way to drive current
through water for purification purposes, because it is
"electrodeless", but I still prefer the tank circuit capacitive
linkage I've suggested in the past for that purpose.
Horace Heffner
http://www.mtaonline.net/~hheffner/
