Hi folks,

Does anyone here have experience of getting the air out of a mercury barometer column? My barometer looks like this:

http://www.messcom.de/MESSCOM/MDO/pd...0Bedienanl.pdf

I had wondered about putting the whole barometer in a vacuum chamber, but I'm not sure if this will work. Unfortunately there's nowhere to connect a vacuum pump at the top of the column.

Is there anyone with experience here who can give me some tips? So far, I've been trying to avoid taking the barometer apart in case I lose the precious (and slightly dangerous) mercury.

The amount of air inside is enough to change the reading by 10 to 20 mm.

Best wishes,

Chris

"Christopher Tidy" wrote in message
...
Hi folks,

Does anyone here have experience of getting the air out of a mercury
barometer column? My barometer looks like this:

http://www.messcom.de/MESSCOM/MDO/pd...0Bedienanl.pdf

I had wondered about putting the whole barometer in a vacuum
chamber, but I'm not sure if this will work. Unfortunately there's
nowhere to connect a vacuum pump at the top of the column.

Is there anyone with experience here who can give me some tips? So
far, I've been trying to avoid taking the barometer apart in case I
lose the precious (and slightly dangerous) mercury.

The amount of air inside is enough to change the reading by 10 to 20
mm.

Best wishes,

Chris

My German isn't quite good enough to fully translate section 5,
Wartung.

On Wed, 04 Mar 2020 16:26:06 -0500, Jim Wilkins wrote:
"Christopher Tidy" wrote ...
Does anyone here have experience of getting the air out of a mercury
barometer column? My barometer looks like this:

http://www.messcom.de/MESSCOM/MDO/pd...0Bedienanl.pdf

I had wondered about putting the whole barometer in a vacuum
chamber, but I'm not sure if this will work. Unfortunately there's
nowhere to connect a vacuum pump at the top of the column.

Is there anyone with experience here who can give me some tips? So
far, I've been trying to avoid taking the barometer apart in case I
lose the precious (and slightly dangerous) mercury.

The amount of air inside is enough to change the reading by 10 to 20
mm.
....
My German isn't quite good enough to fully translate section 5,
Wartung.

Same here ... however, copy/paste into Google Translate gives ok
results: "5. Maintenance \ Because of the unhindered air access,
the mercury level in the lower vessel oxidizes over time. If the
oxidation has progressed so far that the tip of the scale can no
longer be reliably adjusted to the lower mercury level, the
mercury in the vessel should be removed from the barometer and
cleaned. \ CAUTION! \ The mercury may only be cleaned by
qualified specialist personnel."

A couple of other places talk about sending it in for repair; eg
at the end of section 3, "If it is not possible to remove any air
bubbles that are in front of the air trap or if air has entered
the vacuum chamber, the device must be sent in for repair."

Interestingly, the last paragraph about mercury barometers in
https://en.wikipedia.org/wiki/Barometer#Mercury_barometers
says, "On June 5, 2007, a European Union directive was enacted
to restrict the sale of mercury, thus effectively ending the
production of new mercury barometers in Europe."

--
jiw

On 05/03/2020 07:54, James Waldby wrote:
On Wed, 04 Mar 2020 16:26:06 -0500, Jim Wilkins wrote:
"Christopher Tidy" wrote ...
Does anyone here have experience of getting the air out of a mercury
barometer column? My barometer looks like this:

http://www.messcom.de/MESSCOM/MDO/pd...0Bedienanl.pdf

I had wondered about putting the whole barometer in a vacuum
chamber, but I'm not sure if this will work. Unfortunately there's
nowhere to connect a vacuum pump at the top of the column.

Is there anyone with experience here who can give me some tips? So
far, I've been trying to avoid taking the barometer apart in case I
lose the precious (and slightly dangerous) mercury.

The amount of air inside is enough to change the reading by 10 to 20
mm.
...
My German isn't quite good enough to fully translate section 5,
Wartung.
Same here ... however, copy/paste into Google Translate gives ok
results: "5. Maintenance \ Because of the unhindered air access,
the mercury level in the lower vessel oxidizes over time. If the
oxidation has progressed so far that the tip of the scale can no
longer be reliably adjusted to the lower mercury level, the
mercury in the vessel should be removed from the barometer and
cleaned. \ CAUTION! \ The mercury may only be cleaned by
qualified specialist personnel."

A couple of other places talk about sending it in for repair; eg
at the end of section 3, "If it is not possible to remove any air
bubbles that are in front of the air trap or if air has entered
the vacuum chamber, the device must be sent in for repair."

Interestingly, the last paragraph about mercury barometers in
https://en.wikipedia.org/wiki/Barometer#Mercury_barometers
says, "On June 5, 2007, a European Union directive was enacted
to restrict the sale of mercury, thus effectively ending the
production of new mercury barometers in Europe."

Maybe not worthwhile but there are mercury replacement alloys
https://en.wikipedia.org/wiki/Galinstan

James Waldby on Thu, 5 Mar 2020 07:54:24 -0000
(UTC) typed in rec.crafts.metalworking the following:
On Wed, 04 Mar 2020 16:26:06 -0500, Jim Wilkins wrote:
"Christopher Tidy" wrote ...
Does anyone here have experience of getting the air out of a mercury
barometer column? My barometer looks like this:

http://www.messcom.de/MESSCOM/MDO/pd...0Bedienanl.pdf

I had wondered about putting the whole barometer in a vacuum
chamber, but I'm not sure if this will work. Unfortunately there's
nowhere to connect a vacuum pump at the top of the column.

Is there anyone with experience here who can give me some tips? So
far, I've been trying to avoid taking the barometer apart in case I
lose the precious (and slightly dangerous) mercury.

The amount of air inside is enough to change the reading by 10 to 20
mm.
...
My German isn't quite good enough to fully translate section 5,
Wartung.

Same here ... however, copy/paste into Google Translate gives ok
results: "5. Maintenance \ Because of the unhindered air access,
the mercury level in the lower vessel oxidizes over time. If the
oxidation has progressed so far that the tip of the scale can no
longer be reliably adjusted to the lower mercury level, the
mercury in the vessel should be removed from the barometer and
cleaned. \ CAUTION! \ The mercury may only be cleaned by
qualified specialist personnel."

That is boilerplate to protect the company. "As Everybody knows"
touching mercury results in your instantaneous poisoning, tremors,
brain damage, and voting to leave the Glorious EU.

--
pyotr filipivich
"With Age comes Wisdom. Although far too often, Age travels alone."

James Waldby on Thu, 5 Mar 2020 07:54:24 -0000
(UTC) typed in rec.crafts.metalworking the following:

Same here ... however, copy/paste into Google Translate gives ok
results: "5. Maintenance \ Because of the unhindered air access,
the mercury level in the lower vessel oxidizes over time. If the
oxidation has progressed so far that the tip of the scale can no
longer be reliably adjusted to the lower mercury level, the
mercury in the vessel should be removed from the barometer and
cleaned. \ CAUTION! \ The mercury may only be cleaned by
qualified specialist personnel."

A couple of other places talk about sending it in for repair; eg
at the end of section 3, "If it is not possible to remove any air
bubbles that are in front of the air trap or if air has entered
the vacuum chamber, the device must be sent in for repair."

Interestingly, the last paragraph about mercury barometers in
https://en.wikipedia.org/wiki/Barometer#Mercury_barometers
says, "On June 5, 2007, a European Union directive was enacted
to restrict the sale of mercury, thus effectively ending the
production of new mercury barometers in Europe."

Aha! Bwahahahaha.

This is the metal working group, yes?

So of course, check out Cinnabar.

All you have to do is crush the ore and roast it.

"The process of extraction of the mercury is relatively simple. An
oxygen furnace can be used to heat up the ore cinnabar and condenses
the fumes of mercury released from the process."

Better than buying the stuff in a store, and "you made it
yourself!"
--
pyotr filipivich
"With Age comes Wisdom. Although far too often, Age travels alone."

On Wed, 04 Mar 2020 12:41:28 -0800, Christopher Tidy wrote:

Hi folks,

Does anyone here have experience of getting the air out of a mercury
barometer column?
The standard procedure is to turn it upside down, use an eyedropper to
fill the bottom of the tube, and poke a wire down the column to knock any
air bubbles loose. Then, the TRICKY part is to get the tube back right-
side-up without allowing the mercury to escape and air to get back in.

It seems impossible to do this without getting your hands in the mercury.

Jon

On Thu, 05 Mar 2020 08:39:26 -0800, pyotr filipivich wrote:
James Waldby ... on Thu, 5 Mar 2020 07:54:24 -0000 ...:
On Wed, 04 Mar 2020 16:26:06 -0500, Jim Wilkins wrote:
"Christopher Tidy" wrote ...
Does anyone here have experience of getting the air out of a mercury
barometer column? My barometer looks like this:
http://www.messcom.de/MESSCOM/MDO/pd...0Bedienanl.pdf

I had wondered about putting the whole barometer in a vacuum
chamber, but I'm not sure if this will work. Unfortunately there's
nowhere to connect a vacuum pump at the top of the column.

Is there anyone with experience here who can give me some tips? So
far, I've been trying to avoid taking the barometer apart in case I
lose the precious (and slightly dangerous) mercury.

The amount of air inside is enough to change the reading by 10 to 20
mm.
...
My German isn't quite good enough to fully translate section 5,
Wartung.

Same here ... however, copy/paste into Google Translate gives ok
results: "5. Maintenance \ Because of the unhindered air access,
the mercury level in the lower vessel oxidizes over time. If the
oxidation has progressed so far that the tip of the scale can no
longer be reliably adjusted to the lower mercury level, the
mercury in the vessel should be removed from the barometer and
cleaned. \ CAUTION! \ The mercury may only be cleaned by
qualified specialist personnel."

That is boilerplate to protect the company. "As Everybody knows"
touching mercury results in your instantaneous poisoning, tremors,
brain damage, and voting to leave the Glorious EU.

It could well be legalistic boilerplate. However, I think there are
two issues with air in the barometer. Section 3 (which got snipped)
is about trapped bubbles of air. Section 5 is about oxidized mercury,
which apparently is fairly toxic.[1]
[1] https://en.wikipedia.org/wiki/Mercury(II)_oxide#Health_issues

Pulling a vacuum on the mix of mercury and mercury oxide - if that's
what's in the barometer and causing problems - wouldn't remove the HgO,
I think. HgO is about 2/3 as dense as Hg so would expand the volume
when present. Christopher, is that consistent with the symptoms?

--
jiw

On Thursday, March 5, 2020 at 4:55:51 PM UTC-5, Jon Elson wrote:
On Wed, 04 Mar 2020 12:41:28 -0800, Christopher Tidy wrote:

Hi folks,

Does anyone here have experience of getting the air out of a mercury
barometer column?
The standard procedure is to turn it upside down, use an eyedropper to
fill the bottom of the tube, and poke a wire down the column to knock any
air bubbles loose. Then, the TRICKY part is to get the tube back right-
side-up without allowing the mercury to escape and air to get back in.

It seems impossible to do this without getting your hands in the mercury.

Jon

Is there any legal way to ship small amounts of Mercury? I have about a dozen mercury switches from old wall thermostats.

On Thu, 05 Mar 2020 15:55:43 -0600, Jon Elson
wrote:

On Wed, 04 Mar 2020 12:41:28 -0800, Christopher Tidy wrote:

Hi folks,

Does anyone here have experience of getting the air out of a mercury
barometer column?
The standard procedure is to turn it upside down, use an eyedropper to
fill the bottom of the tube, and poke a wire down the column to knock any
air bubbles loose. Then, the TRICKY part is to get the tube back right-
side-up without allowing the mercury to escape and air to get back in.

It seems impossible to do this without getting your hands in the mercury.

Jon
I think nitrile gloves will work just fine to keep mercury from
touching your skin. As long as it is not methyl mercury. A drop on a
rubber glove will still kill you. Slowly. Like in a few weeks.
Eric

Try holding the mercury barometer on its side or to the point where the air can pass to its neutral state, while rotating it as it comes together etc, like water in a glass tube

Am Donnerstag, 5. März 2020 22:55:51 UTC+1 schrieb Jon Elson:

The standard procedure is to turn it upside down, use an eyedropper to
fill the bottom of the tube, and poke a wire down the column to knock any
air bubbles loose. Then, the TRICKY part is to get the tube back right-
side-up without allowing the mercury to escape and air to get back in.

The wire and eye dropper are neat ideas. The problem is getting the reservoir back over the end of the column while the whole thing is in the inverted position. The reservoir is glued together, and I wonder if originally the column was filled first, then the bottomless reservoir was mounted and filled, and finally the bottom of the reservoir was glued on. But I'm reluctant to try and dismantle the reservoir. I think I might damage it.

It seems impossible to do this without getting your hands in the mercury.

Never did me any harm in the past.

Chris

Am Donnerstag, 5. März 2020 22:56:38 UTC+1 schrieb James Waldby:
On Thu, 05 Mar 2020 08:39:26 -0800, pyotr filipivich wrote:
James Waldby ... on Thu, 5 Mar 2020 07:54:24 -0000 ...:
On Wed, 04 Mar 2020 16:26:06 -0500, Jim Wilkins wrote:
"Christopher Tidy" wrote ...
Does anyone here have experience of getting the air out of a mercury
barometer column? My barometer looks like this:
http://www.messcom.de/MESSCOM/MDO/pd...0Bedienanl.pdf

I had wondered about putting the whole barometer in a vacuum
chamber, but I'm not sure if this will work. Unfortunately there's
nowhere to connect a vacuum pump at the top of the column.

Is there anyone with experience here who can give me some tips? So
far, I've been trying to avoid taking the barometer apart in case I
lose the precious (and slightly dangerous) mercury.

The amount of air inside is enough to change the reading by 10 to 20
mm.
...
My German isn't quite good enough to fully translate section 5,
Wartung.

Same here ... however, copy/paste into Google Translate gives ok
results: "5. Maintenance \ Because of the unhindered air access,
the mercury level in the lower vessel oxidizes over time. If the
oxidation has progressed so far that the tip of the scale can no
longer be reliably adjusted to the lower mercury level, the
mercury in the vessel should be removed from the barometer and
cleaned. \ CAUTION! \ The mercury may only be cleaned by
qualified specialist personnel."

That is boilerplate to protect the company. "As Everybody knows"
touching mercury results in your instantaneous poisoning, tremors,
brain damage, and voting to leave the Glorious EU.

It could well be legalistic boilerplate. However, I think there are
two issues with air in the barometer. Section 3 (which got snipped)
is about trapped bubbles of air. Section 5 is about oxidized mercury,
which apparently is fairly toxic.[1]
[1] https://en.wikipedia.org/wiki/Mercury(II)_oxide#Health_issues

Pulling a vacuum on the mix of mercury and mercury oxide - if that's
what's in the barometer and causing problems - wouldn't remove the HgO,
I think. HgO is about 2/3 as dense as Hg so would expand the volume
when present. Christopher, is that consistent with the symptoms?

There's a little oxide in there, but the main problem is that the barometer lay flat for years and was shaken around during a move.

Chris

Am Freitag, 6. März 2020 03:29:19 UTC+1 schrieb :
Try holding the mercury barometer on its side or to the point where the air can pass to its neutral state, while rotating it as it comes together etc, like water in a glass tube

I've tried this. It seems that the reservoir is unfortunately too large (compared to the volume of mercury) for this to work.

Chris

Am Donnerstag, 5. März 2020 13:25:47 UTC+1 schrieb David Billington:

Maybe not worthwhile but there are mercury replacement alloys
https://en.wikipedia.org/wiki/Galinstan

Interesting, but the density would be wrong for the barometer.

Chris

Thanks for all the responses. I'm pondering the vacuum pump idea. Can anyone see a reason why I shouldn't put the barometer in a vacuum chamber (and then probably lie it down and bring it back to the vertical to remove the last traces of air)?

Or connect a pump directly to the reservoir (so long as I make sure the mercury can't go into the pump)?

Chris

Christopher Tidy writes:

Or connect a pump directly to the reservoir (so long as I make sure
the mercury can't go into the pump)?

Exhaust the pump out of doors? Vapor pressure of Hg at room temp is
not negligible so as you approach vacuum, you're sucking and
exhausting more and more Hg molecules.

Just a thought...

--
Mike Spencer Nova Scotia, Canada