[Clayart] pyrometers

[Hank Murrow]

Dear Clayart gang;

A couple of times long ago, but not far away(college at U of Oregon), I had an analog meter stick. I have never had(since 1981) my digital OxyProbe stick with its type S thermocouples; 

and I have increasingly found it useful to log my kiln through soaking cycles in Oxidation during the cooling, after the cones have gone down. IMHO, the type S Platinum/Rhodium 

thermocouples have never lied to me, though I rely on the (guard)Cone 11 to tell me when to shut off the kiln initially, before soaking when the meter says it is 1900F. Thus I have 

very complete records with which to consider why my firing results are the way they turn out. Would not willingly abandon the use of both the OxyProbe and Cones in my work.

YMMV; and until something more useful comes along, this will continue to be my practice.  Also, I like the smell of reduction when I go out through the studio to check the kiln in its shed.

Cheers from Eugene, Hank Murrow




> On Nov 11, 2020, at 11:22 AM, ronroy at ca.inter.net wrote:
> 
> That's strange - I've been using pyrometers for over 60 yeras and have never has one stick. I do agree that cones should decide when to decide to stop firing.
> 
> And yes - very helpful when deciding to increase heat to keep keep the firing moving up.
> 
> They are very helpful when deciding to go into reduction, when to start and stop a cooling slowdown.
> 
> In those 60 years I have had to change a failed themocouple on the fly a couple of time. Always a good idea to have spare parts.
> 
> Anyone who has experienced bisque dunting will need to know when to slow cooling to avoid uneven volume changes at 573C.
> 
> Never a bad idea to understand what is going on in kilns and when.
> 
> RR
> 
> 
> Quoting mel jacobson <melpots at mail.com>:
> 
>> it is amazing how many times we are surprised here at the farm
>> with a stuck pyrometer.  "oh, my god, cone nine is over, the pyrometer
>> is stuck."   cones are `it` for us.  watch them...see color, watch the
>> back pressure, and remember the pyrometer is a `helper` to know what is going on.
>> tap the glass, move the lead, pull it out an inch. it all helps.
>> 
>> we always use cones 9 10 11.  and then we try to make each firing identical.
>> mel
>> i do not appreciate surprises. so, i watch it all. start with color, back pressure
>> and move the damper a tiny bit.  it is a dance.
>> 
>> and always remember, those pyrometer thermocouples die in electric kilns.
>> and most folks with controllers live and die by the gauge.
>> cones
>> 
>> 
>> 
>> website: www.melpots.com
>> www.melpots.com/CLAYART.HTML
>> 
>> 
> 
> 
> 
> Ron Roy
> ronroy at ca.inter.net
> Web page ronroy.net
> 
> 
>