John Baymore on wed 16 jul 03
Linda, my oxyprobe is doing the same thing. In the last firing I had to d=
ig
up an old pyrometer to use because I couldn't get reading of temperature
with
it. And like you, I had no trouble with the atmosphere readings.<
Many people are not aware that oxyprobes are not "fire it and forget it"
devices. Beacuse they seem so expensive .... it seems like they should
just go on and on like the Energizer Bunny . They eventually do need
some maintenence. They typically need some work after about 100 firings
give or take. The "repair" cost about $100. So the real "cost" to opera=
te
one is about $1.00 per firing....plus the amortized cost of the
depreciation of the unit over it's life. =
They are also a tad fragile and the sensor end of things doesn't like to
get too banged around.
best,
.......................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086-5812 USA
JBaymore@compuserve.com
http:\\www.JohnBaymore.com
603-654-2752 (studio)
800-900-1110 (studio)
"Earth, Water, and Fire =
Noborigama Woodfiring Workshop: August 15-24, 2003" =
Hank Murrow on wed 16 jul 03
On Wednesday, July 16, 2003, at 09:10 AM, John Baymore wrote:
>
> Linda, my oxyprobe is doing the same thing. In the last firing I had
> to dig
> up an old pyrometer to use because I couldn't get reading of
> temperature
> with
> it. And like you, I had no trouble with the atmosphere readings.<
>
>
> Many people are not aware that oxyprobes are not "fire it and forget
> it"
> devices. Beacuse they seem so expensive .... it seems like they should
> just go on and on like the Energizer Bunny . They eventually do
> need
> some maintenence. They typically need some work after about 100
> firings
> give or take. The "repair" cost about $100. So the real "cost" to
> operate
> one is about $1.00 per firing....plus the amortized cost of the
> depreciation of the unit over it's life.
>
> They are also a tad fragile and the sensor end of things doesn't like
> to
> get too banged around.
>
Dear John and Linda;
Often the OxyProbes fail where the platinum return wire exits the end
of the tube in the kiln and is exposed to the atmosphere. The OxyProbe
can have the life of its return wire considerably lengthened by
covering the inner tube with another, slightly longer alumina tube to
cover the platinum return wire. Nils or others can sell you a 1/2"
diameter open ended tube for $30+ that you can very lightly cement onto
the original tube and over the platinum return wire. This will prevent
the brittleness and consequent breaking of the wire. I have gotten 200+
fires from mine so far. I beliebve the new Axner units come with the
tube installed. In any case, the repair of a broken wire can be done by
any competent jeweler....mine was welded back for $30.
Cheers, Hank in Eugene
www.murrow.biz/hank
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