7
Ramp-Hold
Mode
Theory of Operation
The temperature you are firing to is called the target
temperature. After the controller reaches the target tem-
perature, it can also hold that temperature.
The controller fires at a controlled heating rate. The rate
is figured in degrees per hour. If you selected a rate of 100°
per hour, it would take 10 hours for the kiln to reach 1000°.
Rate is similar to “miles per hour.”
In summary, the controller does three basic tasks:
1) It fires at a controlled heating rate, or speed, mea-
sured in degrees of temperature change per hour.
2) It fires to a target temperature.
3) It can hold the target temperature.
The controller fires in segments, or stages. A segment is
a given heating rate to a target temperature. Shown in the
chart above is a segment with a target temperature of 1250°
and a rate of 625°, with a hold of one hour.
Heating rate is figured in degrees per hour. The recom-
mended heating rate for the material you are firing is usu-
ally available from your supplier. It also varies depending
on the thickness of the material.
To figure how long a firing segment will take, subtract
the current temperature from the target temperature and
divide the resultant temperature by the heating rate. In the
diagram above, the firing time is 1250° - 80° (room tempera-
ture) = 1170 ÷625 = 1.87 hours.
The controller can fire up to 8 segments per firing. One
segment is often all that is needed, though.
After the controller has finished firing the last segment,
it will turn off power to the elements.
Note:
If you enter a rate of 0000 in segment 1, or if the
target temperature in segment 1 is lower than the cur-
rent temperature,
will appear in the display.
When the Kiln Shuts Off
Too Soon
If the kiln shuts off before the pyrometric witness cone
bends, you can turn the hot kiln back on and keep firing.
Press
twice.
From
, program the next hotter cone in
Cone-Fire.
will appear. To begin firing, press
.
will appear and the Run indicator light will
begin blinking. The hot kiln will begin firing, taking
up where it left off.
How to Customize Cone-Fire
You can customize a Cone-Fire program using
Ramp-Hold. (See the next section.) On pages 15 and 16, ta-
bles show the segments used to program each cone number
in Cone-Fire. For instance, a cone 016 firing at medium
speed (
)uses these two segments:
Rate
Temp.
Segment
°F/°C
°F/°C
Hold
1
396 / 220
1314 / 712
00.00
2
108 / 60
1422 / 772
00.00
Suppose your 016 witness cone, at a medium speed fir-
ing, only barely started to bend. To fire 25° hotter, raise the
target temperature of segment 2 by 25°:
1422 + 25 = 1447
This is the program you would enter in Ramp-Hold:
Rate
Temp.
Segment
°F/°C
°F/°C
Hold
1
396 / 220
1314 / 712
00.00
2
108 / 60
1447 / 786
00.00
You could also easily add a slow cooling segment:
Rate
Temp.
Segment
°F/°C
°F/°C
Hold
1
396 / 220
1314 / 712
00.00
2
108 / 60
1447 / 786
00.00
3
100 / 55
1000 / 537
00.00
