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- Newsgroups: sci.physics.fusion
- Path: sparky!uunet!haven.umd.edu!darwin.sura.net!sgiblab!pacbell.com!UB.com!zorch!fusion
- From: logajan@anubis.network.com (John Logajan)
- Subject: The Trouble with Bubbles. A report.
- Message-ID: <9211231736.AA29089@anubis.network.com>
- Sender: scott@zorch.SF-Bay.ORG (Scott Hazen Mueller)
- Reply-To: logajan@anubis.network.com (John Logajan)
- Organization: Sci.physics.fusion/Mail Gateway
- Date: Mon, 23 Nov 1992 22:00:01 GMT
- Lines: 85
-
- The Trouble with Bubbles.
-
- A preliminary report on a 0.6m K2CO3+H2O/Ni/Pt gas measuring experiment.
-
- Synopsis: Gas evolution rate varied up to 30% using a fixed electrical
- current -- calling into question the 1.48*I assumption.
-
- I figured I could do some comparative electrolysis gas production
- measurements with some simple equipment (see apparatus description below.)
-
- I figured I could count bubbles if they were not too fast nor too slow.
- My apparatus produced bubbles at the rate of about 1-2 per second, which
- was just about ideal for eyeball/wristwatch, lucky me.
-
- I applied 200ma (measured with two different meters both within 0.5% of
- each other) in the reverse current direction (Ni as the anode, Pt as
- cathode.) After one hour the bubble rate was 111 bubbles per minute.
-
- I applied 200ma in the forward current direction (Ni as the cathode, Pt as
- the anode.) After eight hours (sleep), the bubble rate was 88 bubbles
- per minute.
-
- The bubble rate is in a state of flux just after reversing the current
- and takes about an hour or two to settle down.
-
- *Conclusions* -- Any assumption about a fixed relationship between current
- and gas production is (preliminarily) shown to be off by as much as 30%
- (with an approx 10% worst case range of measurement errors.)
-
- Other observations: I continue to get some sort of "fuel cell" effect.
- That is, I get an EMF potential after disconnecting the power supply. It
- decays quickly from around a volt or so to about 1/10 of a volt in the
- course of about 10 seconds (which probably has something to do with the
- load of the voltmeter.)
-
- Furthermore, I continue to get current flow at *all* applied voltage levels.
- This implies either parallel current paths in the electrolyte, or the effect
- of recombination of the gases.
-
- In either case, the 1.48*I factor is (preliminarily) shown to be unreliable
- by a wide margin.
-
- * * * * *
-
- Apparatus consists of:
-
- 1.) A glass test-tube approx 1" x 6" and black rubber stopper (sold as a
- unit as pet mouse water supply.) The test-tube contains:
- a.) Two wires, one Pt and one nickel plated copper.
- b.) Nickel nodules.
- c.) 0.6 molar K2CO3+H2O
-
- 2.) An 8" length of clear flexible soft plastic tropical fish air hose, approx
- 5/32" O.D. 3/32" I.D.
-
- 3.) An old clear glass olive jar approx 2.5" x 6" -- filled with tap water.
-
- 4.) Approx 2-3 ounces of Nickel metal spherical "nodules" each on the
- order of 1/4" diameter.
-
- 5.) A foot of 22 gauge copper wire with nickel plating.
-
- 6.) A 20" length of #30 gauge Platinum wire.
-
- 7.) A manual voltage adjust power supply with built in milliamp meter.
-
- 8.) A Heathkit digital multimeter.
-
- The power supply is connected to the two wires piercing the rubber stopper.
- The nickel plated copper wire descends to the bottom and is in contact with
- the nickel nodules also settled at the bottom. The platinum wire is wound
- loosely in the top section of the test tube. The tube is filled to within
- 1/2" of the top with the K2CO3 solution.
-
- The plastic hose exits the rubber stopper and descends into the water
- filled olive jar. At 200ma input current, bubbles ascend from the hose
- exit in the olive jar at rate of 1-2 per second.
-
- Barometric pressure, ambient temperature, granularity of bubble counts,
- accuracy of current measurement, and accuracy of timing operations add to
- approximately a total worst case error range of 10%.
-
-
- - John Logajan MS010, Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428
- - logajan@network.com, 612-424-4888, Fax 612-424-2853
-