James Roche on sun 7 nov 99
Hello John,
At 20:49 06/11/99 EST, you wrote:
>It is pretty hard to determine levels of junk coming out of
kilns and getting into the air accurately without actual air
sampling. Since most of us don't want to go to the expense of
this........
When I worked as a pharmaceutical chemist in the NHS, one of my
jobs was to ensure that medical gases supplied to wards/theatres
were not mixed up. There were a few disasters many years ago
when the fittings for compressed air, nitrous oxide, oxygen were
very similar, so you could misconnect a line - to the patients
demise.
We used a relatively cheap and highly sensitive solution to
testing any gases: Draeger tubes with a rubber sniffer. You buy
the Draeger tubes in packs of 20, these are glass tubes packed
with a chemical reagent that changes colour on detection of a
particular gas. The rubber sniffer just connected to the glass
tube (after you had snapped off each end), after so many puffs
the correct amount of air was sampled and the reading taken.
I'm sure these are still made, and available internationally.
So they are still a good choice to detect SO2, CO, or anything
else at a reasonably cheap outlay, without expensive equipment.
If anyone is really worried about kiln gases, that's definitely
what I'd use.
James
Evan Dresel on mon 8 nov 99
The trouble with Draeger tubes is that you have to know what gases you
are looking for. Each tube is sensitive to only a single compound or a
few similar compounds. I don't know what all crud comes off during
firing but if you can narrow it down to a few of the possible compounds
they might be useful.
-- Evan in W Richland WA where the winter grey overcast hanging around
your ears is back.
James Roche wrote:
>
> ----------------------------Original message----------------------------
> Hello John,
>
> At 20:49 06/11/99 EST, you wrote:
> >It is pretty hard to determine levels of junk coming out of
> kilns and getting into the air accurately without actual air
> sampling. Since most of us don't want to go to the expense of
> this........
>
> When I worked as a pharmaceutical chemist in the NHS, one of my
> jobs was to ensure that medical gases supplied to wards/theatres
> were not mixed up. There were a few disasters many years ago
> when the fittings for compressed air, nitrous oxide, oxygen were
> very similar, so you could misconnect a line - to the patients
> demise.
>
> We used a relatively cheap and highly sensitive solution to
> testing any gases: Draeger tubes with a rubber sniffer. You buy
> the Draeger tubes in packs of 20, these are glass tubes packed
> with a chemical reagent that changes colour on detection of a
> particular gas. The rubber sniffer just connected to the glass
> tube (after you had snapped off each end), after so many puffs
> the correct amount of air was sampled and the reading taken.
>
> I'm sure these are still made, and available internationally.
> So they are still a good choice to detect SO2, CO, or anything
> else at a reasonably cheap outlay, without expensive equipment.
>
> If anyone is really worried about kiln gases, that's definitely
> what I'd use.
>
> James
James Roche on thu 11 nov 99
Hello Evan,
At 16:54 08/11/99 EST, Evan Dresel wrote:
>The trouble with Draeger tubes is that you have to know what
gases you are looking for.
Well yes that's true, each tube type is manufactured to
specifically detect a particular gas (or small range of related
compounds).
What I was trying to say was, if a potter is concerned about
carbon monoxide levels due to incomplete combustion, or acidic
SO2 fumes, then Draeger tubes are (AFAIK today) the cheapest way
to QUANTIFY the level of gas you're testing in PPM. You can
thus determine if the installation is safe or not.
By looking at their catalogue, you can determine what can be
tested and go from there.
For an exhaustive :) analysis of kiln exhaust gases you're
looking at high-tech analytical chemistry GLC, HPLC, AA, IR, UV,
etc, with all the costs involved. Someone, somewhere has
already done this for sure. Any leads out there?
James
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