seger (ili pirometrska) piramida za određivanje temperature


http://www.clay-king.com/kiln_supplies/kiln_supplies/pyromet...

--------------------------------------------------
Note added at 1 day7 hrs (2014-12-05 14:43:10 GMT)
--------------------------------------------------

Why Use Pyrometric Cones
Cones have been used in firing ceramics for more than 100 years. They are useful because they can determine when a firing is complete, or if the kiln was provided enough heat, or if there is a temperature difference in the kiln, or if a problem occurred during the firing.
What is a Cone?
Cones are slender pyramids made from about 100 carefully controlled compositions. They bend in a repeatable manner over a relatively small temperature range (less than 50°F). The final bending position is a measure of the amount of heat absorbed. We refer to one cone number as being hotter or cooler than another. The coolest cone number is O22 and the hottest is 42. The first cones were numbered from 1 to 20. When cooler cones were developed, an 'O' was placed before the number. So cones cooler than Cone 1 increase from O1 to O2, etc. to O22.
Cone Bending
Both temperature and time and sometimes atmosphere affect the final bending position of a cone. Temperature is the predominant variable. We refer to the temperature as an equivalent temperature, since actual firing conditions may vary somewhat from those in which the cones were originally standardized. Using charts available from Orton, an equivalent temperature can be determined by measuring the final bending position of the Cone, if the heating rate is known. Orton Self-Supporting Cones duplicate their bending behavior with a standard deviation of 2.4 angular degrees or less than + 2°C.
How are Cones Used?
Cones are used as witness cones located on a kiln shelf near the ware or in a kiln shut off device (e.g. Kiln-Sitter®). The cone bends when glass forms and it becomes soft. The composition of the cone and the amount of heat determine when and how much glass if formed. It is important to note that it is the weight of the sensing rod that causes the cone (or bar) in a Kiln-Sitter® to bend. Changes in weight affect the bending of the cone. A witness cone bends because of gravity acting on it. Therefore, mounting height and angle is important. The higher the cone or the more it leans over at the start, the more gravity affects bending, causing early bending. It is for this reason Orton developed Self-supporting witness cones some 20 years ago, where mounting height and angle is fixed. It typically takes 15 to 25 minutes for a cone to bend, depending upon the cone number. The cone bends slowly at first but once it reaches the halfway point, it bends quickly. When the cone tip reaches a point level with the base, it is considered properly fired; however, the difference between a cone touching the shelf and a cone at the 4 o'clock position is small and rarely affects the fired results.
Why use Cones?
Firing ceramics is much like baking, except temperatures are higher. Ceramics can be fired over a range of temperatures. Some products have a wide firing range while others have a narrow range. Firing to a slightly lower temperature requires the ware to be held for a longer time, just as it would be done if one were baking a turkey. This is because it takes time for the ware to absorb all of the heat needed to properly "cook" the piece. We refer to this absorption of heat as 'heatwork'. When the amount of heatwork for two firings is the same, the pieces will look identical, even if one is fired to a higher temperature for a short time and another is fired at a lower temperature for a longer time. Since cones measure heatwork, all manufacturers recommend the cone number to which their product should be fired.
Three Cone System
Many products used today, such as porcelain and lead-free glazes, need to be fired within a 2-cone range. The 3-cone system can be used to determine temperature uniformity and to check the performance of the Kiln-Sitter® or electronic controller. The 3-cone system consists of three consecutively numbered cones:

• Firing Cone - cone recommended by manufacturer of glaze, slip, etc.
• Guide Cone - one cone number cooler than firing cone.
• Guard Cone - one cone number hotter than firing cone.
For example: Cones O17, O18, O19 or Cones 5, 6, 7.

--------------------------------------------------
Note added at 1 day7 hrs (2014-12-05 14:48:13 GMT)
--------------------------------------------------


Fire cone number: not applicable

Broj seger piramide (konusa) za određivanje temperature ili
Broj pirometarske piramide (konusa)


--------------------------------------------------
Note added at 1 day8 hrs (2014-12-05 14:55:20 GMT)
--------------------------------------------------

http://en.bab.la/dictionary/english-german/seger-cone

fire cone number = broj segerove piramide, segerova piramida broj
https://fedorabg.bg.ac.rs/fedora/get/o:7395/bdef:Content/get
UNIVERZITET U BEOGRADU
TEHNOLOŠKO – METALURŠKI FAKULTET
---
Vatrostalnost nije fizička već tehnička konstanta materijala. Oznaka vatrostalnosti je SK (Segerova piramida – trostrana piramida visine 30 mm ili 62 mm, čiji je sastav poznat i takav da do deformacije dolazi na određenoj temperaturi) i broj koji predstavlja šifru za temperaturu (npr. SK17). Temperature koje odgovaraju konkretnim oznakama Segerovih piramida nalaze se u aktuelnim standardima. Za temperaturu omekšavanja ili početka deformacije jednog vatrostalnog betona usvaja se temperatura piramide koja se istovremeno savila (vrhom dodirnula nosač) kad i posmatrani uzorak betona. U slučaju da vatrostalnostuzorka vatrostalnog betona leži između dve vrednosti Segerovih piramida, vatrostalnost seodređuje interpolacijom.

https://www.baileypottery.com/cones/cones1.htm
A Fire Cone - The cone number you wish to achieve.

--------------------------------------------------
Note added at 1 day8 hrs (2014-12-05 15:18:25 GMT)
--------------------------------------------------

Yaboravila sam da navedem ovaj link:
http://books.google.rs/books?id=a05NAvaqfcUC&pg=PA601&lpg=PA...
The German ceramist Seger invented the first pyrometric cone in 1886.

fire cone = pyrometric cone, ovde je sve objašnjeno:
http://askteresagriffin.blogspot.com/2010/11/pyrometric-cone...
Pyrometric Cone Chart
For ceramics, kilns are not fired just to a temperature. They are fired to a "cone" level, which accounts for time as well as temperature. Think of it as heat absorption rather than just temperature.
Cone's come in different numbers, each of which corresponds to a heating-rate/temperature-combination which will make that cone deform. At the beginning of the firing the cone is standing at an 8 degree angle. A perfectly fire cone will be bent to a 90 degree angle. If the cone is bent less, the kiln was under fired. If the cone is bent more, the kiln was over fired.
Notice the way the cones are numbered. The hottest is 10, going downward to 1. Then as it continues to getting cooler it continues at 01, 02, etc. So there is a BIG difference between cone 5 and cone 05!