chemrox
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glassware holding a magnetic field (?)
I observed a strange phenomenon in my lab this morning. I had cleaned and oven dried an evaporation flask (1000 ml). I needed to weigh it in order
to calculate how many mmols of product I had. As I started to set the flask on my Sartorious/Acculab analytical balance the balance started jumping
upwards erratically. I called Sartorious and the man I spoke with said he hadn't heard of that in ~40 years. I leaned it against a grounded outlet
bracket for about 1.5 hrs and noticed the balnce still read upwards with increasing proximity to the balance pan but the response was much weaker. I
have attached it to a clamp that is in contact with the outlet bracket. I will check it again tomorrow. If anyone understands the physics of this
please reply or drop me a line.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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JohnWW
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Borosilicate glass as used in lab glassware should not contain any paramagnetic, let alone ferromagnetic, substances. If the balance is jumping around
erratically like that, it may be due to an electric motor or generator operating in the close vicinity.
[Edited on 14-4-10 by JohnWW]
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chief
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I had such experiences when mixing H2SO4 with water on a electronic balance ...
==> Then I started to wonder abut possible electromagnetic radiation ...
After all it's known that some reactions emit light ...
==> So also maybe each other reaction emits some sort of em-radiation, maybe in the THz/GHz or even MHz-Range ...
That would permit to construct strong chemical MASERS, by putting the reaction into an resonator ...
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bahamuth
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I see this all the time, if I understand you correct.
I believe it to me static electricity of sorts, usually this phenomena occurs when I use polystyrene spatulas/spoons and if someone has spilled alot
of chemicals and not cleaned it properly, so I fix it by either touching the weighing plate with my bare hands or a metal object, and/or clean it
properly with IPA/NH3 solution.
The analytical balances work by the changing Resistance or voltage in a alloy bar which is almost drilled in two inside the balance, so any static
would likely affect it. So if I am correct it sounds plausible that the balance shows erratic readings as the static electricity leaves or
accumulates.
Hope this helps..
Any sufficiently advanced technology is indistinguishable from magic.
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chief
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Anyhow a good spectrum analyzer would be a nice tool (that works in the GHz-range), to let chemical reactions take place between 2 electrodes or
within a coil ...
==> Maybe something could be found ...
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Mr. Wizard
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I too would check for static electricity on the face of the gauge. A quick wipe with a moistened paper towel, or even exhaling very softly close to
the plastic face will allow the charge to flow away. They used to sell a product that would eliminate static on television screens and plastic. It is
also a problem with analog electric meters with plastic faces.
Grounding the instrument may help, but grounding the instrument, wiping the face with a damp cloth with a slight bit of fabric freshener like used in
clothes driers will do a lot to help. If you are wearing rubber soled shoes in dry air you can be carrying quite a charge too. Ground yourself by
touching a wall or metal plumbing object to lose the charge. Touching a wall is slower but it doesn't give a sharp shock as would touching a metal
conductor. Do this before you put anything on the scale. This is even more important when pouring flammable liquids such as alcohols which have such
wide explosive limits.
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chemrox
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I took another flask and put it in the same oven for a couple of hours. After letting the flask cool I tried it on the same balance and got the same
result. Obviously the oven imparts some kind of static charge. Borosilicate glass is so free of ferromagnetic material that once the charge is there
its bloody hard to discharge it. An identical flask that hasn't been in the oven recently had no effect on the balance. I don't think the issue is
in the balance at all. A degaussing coil would be nice or would it have any effect?
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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Sedit
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If its static charge a degaussing coil would have no effect where as if it where indeed a magnetic anomally a degaussing coil might perhaps cancel it
out.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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Mr. Wizard
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I know this is too obvious, but have you brought a compass near it? A deflection of a compass is the best evidence of a magnetic field. Failing that,
as the field might be too diffused, you could balance the flask on a glass rod with another flask, and suspend it from a thread. Once the item is
relatively motionless you could see if the flask is attracted to a magnet brought near it.
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